Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

ABSTRACT

The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/120,005, filed Dec. 4, 2008, and U.S. Provisional Application No.61/121,805, filed Dec. 11, 2008, which applications are incorporatedherein by reference.

REFERENCE TO A SEQUENCE LISTING

This application contains a Sequence Listing filed electronically byEFS, which is incorporated herein by reference.

REFERENCE TO A DEPOSIT OF BIOLOGICAL MATERIAL

This application contains a reference to a deposit of biologicalmaterial, which deposit is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to isolated polypeptides havingcellulolytic enhancing activity and isolated polynucleotides encodingthe polypeptides. The invention also relates to nucleic acid constructs,vectors, and host cells comprising the polynucleotides as well asmethods of producing and using the polypeptides.

2. Description of the Related Art

Cellulose is a polymer of the simple sugar glucose linked by beta-1,4bonds. Many microorganisms produce enzymes that hydrolyze beta-linkedglucans. These enzymes include endoglucanases, cellobiohydrolases, andbeta-glucosidases. Endoglucanases digest the cellulose polymer at randomlocations, opening it to attack by cellobiohydrolases.Cellobiohydrolases sequentially release molecules of cellobiose from theends of the cellulose polymer. Cellobiose is a water-solublebeta-1,4-linked dimer of glucose. Beta-glucosidases hydrolyze cellobioseto glucose.

The conversion of lignocellulosic feedstocks into ethanol has theadvantages of the ready availability of large amounts of feedstock, thedesirability of avoiding burning or land filling the materials, and thecleanliness of the ethanol fuel. Wood, agricultural residues, herbaceouscrops, and municipal solid wastes have been considered as feedstocks forethanol production. These materials primarily consist of cellulose,hemicellulose, and lignin. Once the cellulose is converted to glucose,the glucose is easily fermented by yeast into ethanol.

It would be advantageous in the art to improve the ability toenzymatically degrade lignocellulosic feedstocks.

WO 2005/074647 discloses isolated polypeptides having cellulolyticenhancing activity and polynucleotides thereof from Thielaviaterrestris. WO 2005/074656 discloses an isolated polypeptide havingcellulolytic enhancing activity and the polynucleotide thereof fromThermoascus aurantiacus. WO 2007/089290 discloses an isolatedpolypeptide having cellulolytic enhancing activity and thepolynucleotide thereof from Trichoderma reesei.

The present invention provides polypeptides having cellulolyticenhancing activity and polynucleotides encoding the polypeptides.

SUMMARY OF THE INVENTION

The present invention relates to isolated polypeptides havingcellulolytic enhancing activity selected from the group consisting of:

(a) a polypeptide comprising an amino acid sequence having at least 80%sequence identity to the mature polypeptide of SEQ ID NO: 2;

(b) a polypeptide encoded by a polynucleotide that hybridizes under atleast high stringency conditions with (i) the mature polypeptide codingsequence of SEQ ID NO: 1, (ii) the cDNA sequence contained in the maturepolypeptide coding sequence of SEQ ID NO: 1, or (iii) a full-lengthcomplementary strand of (i) or (ii);

(c) a polypeptide encoded by a polynucleotide comprising a nucleotidesequence having at least 80% sequence identity to the mature polypeptidecoding sequence of SEQ ID NO: 1; and

(d) a variant comprising a substitution, deletion, and/or insertion ofone or more (several) amino acids of the mature polypeptide of SEQ IDNO: 2.

The present invention also relates to isolated polynucleotides encodingpolypeptides having cellulolytic enhancing activity, selected from thegroup consisting of:

(a) a polynucleotide encoding a polypeptide comprising an amino acidsequence having at least 80% sequence identity to the mature polypeptideof SEQ ID NO: 2;

(b) a polynucleotide that hybridizes under at least high stringencyconditions with (i) the mature polypeptide coding sequence of SEQ ID NO:1, (ii) the cDNA sequence contained in the mature polypeptide codingsequence of SEQ ID NO: 1, or (iii) a full-length complementary strand of(i) or (ii);

(c) a polynucleotide comprising a nucleotide sequence having at least80% sequence identity to the mature polypeptide coding sequence of SEQID NO: 1; and

(d) a polynucleotide encoding a variant comprising a substitution,deletion, and/or insertion of one or more (several) amino acids of themature polypeptide of SEQ ID NO: 2.

The present invention also relates to nucleic acid constructs,recombinant expression vectors, recombinant host cells comprising thepolynucleotides, and methods of producing the polypeptides havingcellulolytic enhancing activity.

The present invention also relates to methods of inhibiting theexpression of a polypeptide having cellulolytic enhancing activity in acell, comprising administering to the cell or expressing in the cell adouble-stranded RNA (dsRNA) molecule, wherein the dsRNA comprises asubsequence of a polynucleotide of the present invention. The presentalso relates to such a double-stranded inhibitory RNA (dsRNA) molecule,wherein optionally the dsRNA is a siRNA or a miRNA molecule.

The present invention also relates to methods for degrading orconverting a cellulosic material, comprising: treating the cellulosicmaterial with an enzyme composition in the presence of a polypeptidehaving cellulolytic enhancing activity of the present invention. In apreferred aspect, the method further comprises recovering the degradedor converted cellulosic material.

The present invention also relates to methods of producing afermentation product, comprising: (a) saccharifying a cellulosicmaterial with an enzyme composition in the presence of a polypeptidehaving cellulolytic enhancing activity of the present invention; (b)fermenting the saccharified cellulosic material with one or morefermenting microorganisms to produce the fermentation product; and (c)recovering the fermentation product from the fermentation.

The present invention also relates to methods of fermenting a cellulosicmaterial, comprising: fermenting the cellulosic material with one ormore fermenting microorganisms, wherein the cellulosic material issaccharified with an enzyme composition in the presence of a polypeptidehaving cellulolytic enhancing activity of the present invention. In apreferred aspect, the fermenting of the cellulosic material produces afermentation product. In one aspect, the method further comprisesrecovering the fermentation product from the fermentation.

The present invention also relates to plants comprising an isolatedpolynucleotide encoding a polypeptide having cellulolytic enhancingactivity.

The present invention also relates to methods of producing a polypeptidehaving cellulolytic enhancing activity, comprising: (a) cultivating atransgenic plant or a plant cell comprising a polynucleotide encodingthe polypeptide having cellulolytic enhancing activity under conditionsconducive for production of the polypeptide; and (b) recovering thepolypeptide.

The present invention further relates to an isolated polynucleotideencoding a signal peptide comprising or consisting of amino acids 1 to21 of SEQ ID NO: 2; to nucleic acid constructs, expression vectors, andrecombinant host cells comprising the polynucleotides; and to methods ofproducing a protein.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows the genomic DNA sequence and the deduced amino acidsequence of a Thermoascus aurantiacus CGMCC 0670 GH61B polypeptidehaving cellulolytic enhancing activity gene (SEQ ID NOs: 1 and 2,respectively).

FIG. 2 shows a restriction map of pXYG1051-ND001860 long.

FIG. 3 shows a restriction map of pXYZ1473.

FIG. 4 shows the effect of Thermoascus aurantiacus GH61B polypeptidehaving cellulolytic enhancing activity on PCS hydrolysis by a basecellulase mixture. The performance of the base cellulase mix is shown bythe solid line. The effect of adding increasing amounts of theapproximately 25 kDa GH61B polypeptide to the lowest concentration ofthe base cellulase mix (relative protein loading of 1.0) is shown by theline with circles while addition of the approximately 50 kDa GH61Bpolypeptide is represented by the line with squares.

DEFINITIONS

Cellulolytic enhancing activity: The term “cellulolytic enhancingactivity” is defined herein as a biological activity that enhances thehydrolysis of a cellulosic material by polypeptides having cellulolyticactivity. For purposes of the present invention, cellulolytic enhancingactivity is determined by measuring the increase in reducing sugars orthe increase of the total of cellobiose and glucose from the hydrolysisof a cellulosic material by cellulolytic protein under the followingconditions: 1-50 mg of total protein/g of cellulose in PCS, whereintotal protein is comprised of 50-99.5% w/w cellulolytic protein and0.5-50% w/w protein of cellulolytic enhancing activity for 1-7 day at50-65° C. compared to a control hydrolysis with equal total proteinloading without cellulolytic enhancing activity (1-50 mg of cellulolyticprotein/g of cellulose in PCS). In a preferred aspect, a mixture ofCELLUCLAST® 1.5L (Novozymes A/S, Bagsværd, Denmark) in the presence of3% of total protein weight Aspergillus oryzae beta-glucosidase(recombinantly produced in Aspergillus oryzae according to WO 02/095014)or 3% of total protein weight Aspergillus fumigatus beta-glucosidase(recombinantly produced in Aspergillus oryzae as described in WO2002/095014) of cellulase protein loading is used as the source of thecellulolytic activity.

The polypeptides having cellulolytic enhancing activity have at least20%, preferably at least 40%, more preferably at least 50%, morepreferably at least 60%, more preferably at least 70%, more preferablyat least 80%, even more preferably at least 90%, most preferably atleast 95%, and even most preferably at least 100% of the cellulolyticenhancing activity of the mature polypeptide of a GH61 polypeptide.

The polypeptides having cellulolytic enhancing activity enhance thehydrolysis of a cellulosic material catalyzed by proteins havingcellulolytic activity by reducing the amount of cellulolytic enzymerequired to reach the same degree of hydrolysis preferably at least1.01-fold, more preferably at least 1.05-fold, more preferably at least1.10-fold, more preferably at least 1.25-fold, more preferably at least1.5-fold, more preferably at least 2-fold, more preferably at least3-fold, more preferably at least 4-fold, more preferably at least5-fold, even more preferably at least 10-fold, and most preferably atleast 20-fold.

Family 61 glycoside hydrolase: The term “Family 61 glycoside hydrolase”or “Family GH61” is defined herein as a polypeptide falling into theglycoside hydrolase Family 61 according to Henrissat B., 1991, Aclassification of glycosyl hydrolases based on amino-acid sequencesimilarities, Biochem. J. 280: 309-316, and Henrissat B., and BairochA., 1996, Updating the sequence-based classification of glycosylhydrolases, Biochem. J. 316: 695-696.

Cellulolytic activity: The term “cellulolytic activity” is definedherein as a biological activity that hydrolyzes a cellulosic material.The two basic approaches for measuring cellulolytic activity include:(1) measuring the total cellulolytic activity, and (2) measuring theindividual cellulolytic activities (endoglucanases, cellobiohydrolases,and beta-glucosidases) as reviewed in Zhang et al., Outlook forcellulase improvement: Screening and selection strategies, 2006,Biotechnology Advances 24: 452-481. Total cellulolytic activity isusually measured using insoluble substrates, including Whatman No 1filter paper, microcrystalline cellulose, bacterial cellulose, algalcellulose, cotton, pretreated lignocellulose, etc. The most common totalcellulolytic activity assay is the filter paper assay using Whatman No 1filter paper as the substrate. The assay was established by theInternational Union of Pure and Applied Chemistry (IUPAC) (Ghose, 1987,Measurement of cellulase activities, Pure Appl. Chem. 59: 257-68).

For purposes of the present invention, cellulolytic activity isdetermined by measuring the increase in hydrolysis of a cellulosicmaterial by cellulolytic enzyme(s) under the following conditions: 1-20mg of cellulolytic protein/g of cellulose in PCS for 3-7 days at 50-65°C. compared to a control hydrolysis without addition of cellulolyticprotein. Typical conditions are 1 ml reactions, washed or unwashed PCS,5% insoluble solids, 50 mM sodium acetate pH 5, 1 mM MnSO₄, 50-65° C.,72 hours, sugar analysis by AMINEX® HPX-87H column (Bio-RadLaboratories, Inc., Hercules, Calif., USA).

Endoglucanase: The term “endoglucanase” is defined herein as anendo-1,4-(1,3;1,4)-beta-D-glucan 4-glucanohydrolase (E.C. 3.2.1.4),which catalyses endohydrolysis of 1,4-beta-D-glycosidic linkages incellulose, cellulose derivatives (such as carboxymethyl cellulose andhydroxyethyl cellulose), lichenin, beta-1,4 bonds in mixed beta-1,3glucans such as cereal beta-D-glucans or xyloglucans, and other plantmaterial containing cellulosic components. Endoglucanase activity can bedetermined based on a reduction in substrate viscosity or increase inreducing ends determined by a reducing sugar assay (Zhang et al., 2006,Biotechnology Advances 24: 452-481). For purposes of the presentinvention, endoglucanase activity is determined using carboxymethylcellulose (CMC) hydrolysis according to the procedure of Ghose, 1987,Pure and Appl. Chem. 59: 257-268.

Cellobiohydrolase: The term “cellobiohydrolase” is defined herein as a1,4-beta-D-glucan cellobiohydrolase (E.C. 3.2.1.91), which catalyzes thehydrolysis of 1,4-beta-D-glucosidic linkages in cellulose,cellooligosaccharides, or any beta-1,4-linked glucose containingpolymer, releasing cellobiose from the reducing or non-reducing ends ofthe chain (Teeri, 1997, Crystalline cellulose degradation: New insightinto the function of cellobiohydrolases, Trends in Biotechnology 15:160-167; Teeri et al., 1998, Trichoderma reesei cellobiohydrolases: whyso efficient on crystalline cellulose?, Biochem. Soc. Trans. 26:173-178). For purposes of the present invention, cellobiohydrolaseactivity is determined using a fluorescent disaccharide derivative4-methylumbelliferyl-β-D-lactoside according to the procedures describedby van Tilbeurgh et al., 1982, FEBS Letters 149: 152-156 and vanTilbeurgh and Claeyssens, 1985, FEBS Letters 187: 283-288.

Beta-glucosidase: The term “beta-glucosidase” is defined herein as abeta-D-glucoside glucohydrolase (E.C. 3.2.1.21), which catalyzes thehydrolysis of terminal non-reducing beta-D-glucose residues with therelease of beta-D-glucose. For purposes of the present invention,beta-glucosidase activity is determined according to the basic proceduredescribed by Venturi et al., 2002, Extracellular beta-D-glucosidase fromChaetomium thermophilum var. coprophilum: production, purification andsome biochemical properties, J. Basic Microbiol. 42: 55-66. One unit ofbeta-glucosidase activity is defined as 1.0 μmole of p-nitrophenolproduced per minute at 40° C., pH 5 from 1 mMp-nitrophenyl-beta-D-glucopyranoside as substrate in 100 mM sodiumcitrate containing 0.01% TWEEN® 20.

Xylan degrading activity: The terms “xylan degrading activity” or“xylanolytic activity” are defined herein as a biological activity thathydrolyzes xylan-containing material. The two basic approaches formeasuring xylanolytic activity include: (1) measuring the totalxylanolytic activity, and (2) measuring the individual xylanolyticactivities (endoxylanases, beta-xylosidases, arabinofuranosidases,alpha-glucuronidases, acetylxylan esterases, feruloyl esterases, andalpha-glucuronyl esterases). Recent progress in assays of xylanolyticenzymes was summarized in several publications including Biely andPuchard, Recent progress in the assays of xylanolytic enzymes, 2006,Journal of the Science of Food and Agriculture 86(11): 1636-1647;Spanikova and Biely, 2006, Glucuronoyl esterase—Novel carbohydrateesterase produced by Schizophyllum commune, FEBS Letters 580(19):4597-4601; Herrmann, Vrsanska, Jurickova, Hirsch, Biely, and Kubicek,1997, The beta-D-xylosidase of Trichoderma reesei is a multifunctionalbeta-D-xylan xylohydrolase, Biochemical Journal 321: 375-381.

Total xylan degrading activity can be measured by determining thereducing sugars formed from various types of xylan, including oat spelt,beechwood, and larchwood xylans, or by photometric determination of dyedxylan fragments released from various covalently dyed xylans. The mostcommon total xylanolytic activity assay is based on production ofreducing sugars from polymeric 4-O-methyl glucuronoxylan as described inBailey, Biely, Poutanen, 1992, Interlaboratory testing of methods forassay of xylanase activity, Journal of Biotechnology 23(3): 257-270.

For purposes of the present invention, xylan degrading activity isdetermined by measuring the increase in hydrolysis of birchwood xylan(Sigma Chemical Co., Inc., St. Louis, Mo., USA) by xylan-degradingenzyme(s) under the following typical conditions: 1 ml reactions, 5mg/ml substrate (total solids), 5 mg of xylanolytic protein/g ofsubstrate, 50 mM sodium acetate pH 5, 50° C., 24 hours, sugar analysisusing p-hydroxybenzoic acid hydrazide (PHBAH) assay as described byLever, 1972, A new reaction for colorimetric determination ofcarbohydrates, Anal. Biochem 47: 273-279.

Xylanase activity: The term “xylanase activity” is defined herein as a1,4-beta-D-xylan-xylohydrolase activity (E.C. 3.2.1.8) that catalyzesthe endo-hydrolysis of 1,4-beta-D-xylosidic linkages in xylans. Forpurposes of the present invention, xylanase activity is determined usingbirchwood xylan as substrate. One unit of xylanase activity is definedas 1.0 μmole of reducing sugar (measured in glucose equivalents asdescribed by Lever, 1972, A new reaction for colorimetric determinationof carbohydrates, Anal. Biochem 47: 273-279) produced per minute duringthe initial period of hydrolysis at 50° C., pH 5 from 2 g of birchwoodxylan per liter as substrate in 50 mM sodium acetate containing 0.01%TWEEN® 20.

Beta-xylosidase activity: The term “beta-xylosidase activity” is definedherein as a beta-D-xyloside xylohydrolase (E.C. 3.2.1.37) that catalyzesthe exo-hydrolysis of short beta (1→4)-xylooligosaccharides, to removesuccessive D-xylose residues from the non-reducing termini. For purposesof the present invention, one unit of beta-xylosidase activity isdefined as 1.0 μmole of p-nitrophenol produced per minute at 40° C., pH5 from 1 mM p-nitrophenyl-beta-D-xyloside as substrate in 100 mM sodiumcitrate containing 0.01% TWEEN® 20.

Acetylxylan esterase activity: The term “acetylxylan esterase activity”is defined herein as a carboxylesterase activity (EC 3.1.1.72) thatcatalyses the hydrolysis of acetyl groups from polymeric xylan,acetylated xylose, acetylated glucose, alpha-napthyl acetate, andp-nitrophenyl acetate. For purposes of the present invention,acetylxylan esterase activity is determined using 0.5 mMp-nitrophenylacetate as substrate in 50 mM sodium acetate pH 5.0containing 0.01% TWEEN™ 20. One unit of acetylxylan esterase activity isdefined as the amount of enzyme capable of releasing 1 μmole ofp-nitrophenolate anion per minute at pH 5, 25° C.

Feruloyl esterase activity: The term “feruloyl esterase activity” isdefined herein as a 4-hydroxy-3-methoxycinnamoyl-sugar hydrolaseactivity (EC 3.1.1.73) that catalyzes the hydrolysis of the4-hydroxy-3-methoxycinnamoyl (feruloyl) group from an esterified sugar,which is usually arabinose in “natural” substrates, to produce ferulate(4-hydroxy-3-methoxycinnamate). Feruloyl esterase is also known asferulic acid esterase, hydroxycinnamoyl esterase, FAE-III, cinnamoylester hydrolase, FAEA, cinnAE, FAE-I, or FAE-II. For purposes of thepresent invention, feruloyl esterase activity is determined using 0.5 mMp-nitrophenylferulate as substrate in 50 mM sodium acetate pH 5.0. Oneunit of feruloyl esterase activity equals the amount of enzyme capableof releasing 1 μmole of p-nitrophenolate anion per minute at pH 5, 25°C.

Alpha-glucuronidase activity: The term “alpha-glucuronidase activity” isdefined herein as an alpha-D-glucosiduronate glucuronohydrolase activity(EC 3.2.1.139) that catalyzes the hydrolysis of an alpha-D-glucuronosideto D-glucuronate and an alcohol. For purposes of the present invention,alpha-glucuronidase activity is determined according to de Vries, 1998,J. Bacteriol. 180: 243-249. One unit of alpha-glucuronidase activityequals the amount of enzyme capable of releasing 1 μmole of glucuronicor 4-O-methylglucuronic acid per minute at pH 5, 40° C.

Alpha-L-arabinofuranosidase activity: The term“alpha-L-arabinofuranosidase activity” is defined herein as analpha-L-arabinofuranoside arabinofuranohydrolase activity (EC 3.2.1.55)that catalyzes the hydrolysis of terminal non-reducingalpha-L-arabinofuranoside residues in alpha-L-arabinosides. The enzymeactivity acts on alpha-L-arabinofuranosides, alpha-L-arabinanscontaining (1,3)- and/or (1,5)-linkages, arabinoxylans, andarabinogalactans. Alpha-L-arabinofuranosidase is also known asarabinosidase, alpha-arabinosidase, alpha-L-arabinosidase,alpha-arabinofuranosidase, polysaccharide alpha-L-arabinofuranosidase,alpha-L-arabinofuranoside hydrolase, L-arabinosidase, oralpha-L-arabinanase. For purposes of the present invention,alpha-L-arabinofuranosidase activity is determined using 5 mg of mediumviscosity wheat arabinoxylan (Megazyme International Ireland, Ltd.,Bray, Co. Wicklow, Ireland) per ml of 100 mM sodium acetate pH 5 in atotal volume of 200 μl for 30 minutes at 40° C. followed by arabinoseanalysis by AMINEX® HPX-87H column chromatography (Bio-Rad Laboratories,Inc., Hercules, Calif., USA).

Cellulosic material: The cellulosic material can be any materialcontaining cellulose. The predominant polysaccharide in the primary cellwall of biomass is cellulose, the second most abundant is hemicellulose,and the third is pectin. The secondary cell wall, produced after thecell has stopped growing, also contains polysaccharides and isstrengthened by polymeric lignin covalently cross-linked tohemicellulose. Cellulose is a homopolymer of anhydrocellobiose and thusa linear beta-(1-4)-D-glucan, while hemicelluloses include a variety ofcompounds, such as xylans, xyloglucans, arabinoxylans, and mannans incomplex branched structures with a spectrum of substituents. Althoughgenerally polymorphous, cellulose is found in plant tissue primarily asan insoluble crystalline matrix of parallel glucan chains.Hemicelluloses usually hydrogen bond to cellulose, as well as to otherhemicelluloses, which help stabilize the cell wall matrix.

Cellulose is generally found, for example, in the stems, leaves, hulls,husks, and cobs of plants or leaves, branches, and wood of trees. Thecellulosic material can be, but is not limited to, herbaceous material,agricultural residue, forestry residue, municipal solid waste, wastepaper, and pulp and paper mill residue (see, for example, Wiselogel etal., 1995, in Handbook on Bioethanol (Charles E. Wyman, editor), pp.105-118, Taylor & Francis, Washington D.C.; Wyman, 1994, BioresourceTechnology 50: 3-16; Lynd, 1990, Applied Biochemistry and Biotechnology24/25: 695-719; Mosier et al., 1999, Recent Progress in Bioconversion ofLignocellulosics, in Advances in Biochemical Engineering/Biotechnology,T. Scheper, managing editor, Volume 65, pp. 23-40, Springer-Verlag, NewYork). It is understood herein that the cellulose may be in the form oflignocellulose, a plant cell wall material containing lignin, cellulose,and hemicellulose in a mixed matrix. In a preferred aspect, thecellulosic material is lignocellulose.

In one aspect, the cellulosic material is herbaceous material. Inanother aspect, the cellulosic material is agricultural residue. Inanother aspect, the cellulosic material is forestry residue. In anotheraspect, the cellulosic material is municipal solid waste. In anotheraspect, the cellulosic material is waste paper. In another aspect, thecellulosic material is pulp and paper mill residue.

In another aspect, the cellulosic material is corn stover. In anotheraspect, the cellulosic material is corn fiber. In another aspect, thecellulosic material is corn cob. In another aspect, the cellulosicmaterial is orange peel. In another aspect, the cellulosic material isrice straw. In another aspect, the cellulosic material is wheat straw.In another aspect, the cellulosic material is switch grass. In anotheraspect, the cellulosic material is miscanthus. In another aspect, thecellulosic material is bagasse.

In another aspect, the cellulosic material is microcrystallinecellulose. In another aspect, the cellulosic material is bacterialcellulose. In another aspect, the cellulosic material is algalcellulose. In another aspect, the cellulosic material is cotton linter.In another aspect, the cellulosic material is amorphous phosphoric-acidtreated cellulose. In another aspect, the cellulosic material is filterpaper.

The cellulosic material may be used as is or may be subjected topretreatment, using conventional methods known in the art, as describedherein. In a preferred aspect, the cellulosic material is pretreated.

Pretreated corn stover: The term “PCS” or “Pretreated Corn Stover” isdefined herein as a cellulosic material derived from corn stover bytreatment with heat and dilute sulfuric acid.

Isolated polypeptide: The term “isolated polypeptide” as used hereinrefers to a polypeptide that is isolated from a source. In a preferredaspect, the polypeptide is at least 1% pure, preferably at least 5%pure, more preferably at least 10% pure, more preferably at least 20%pure, more preferably at least 40% pure, more preferably at least 60%pure, even more preferably at least 80% pure, and most preferably atleast 90% pure, as determined by SDS-PAGE.

Substantially pure polypeptide: The term “substantially purepolypeptide” denotes herein a polypeptide preparation that contains atmost 10%, preferably at most 8%, more preferably at most 6%, morepreferably at most 5%, more preferably at most 4%, more preferably atmost 3%, even more preferably at most 2%, most preferably at most 1%,and even most preferably at most 0.5% by weight of other polypeptidematerial with which it is natively or recombinantly associated. It is,therefore, preferred that the substantially pure polypeptide is at least92% pure, preferably at least 94% pure, more preferably at least 95%pure, more preferably at least 96% pure, more preferably at least 97%pure, more preferably at least 98% pure, even more preferably at least99% pure, most preferably at least 99.5% pure, and even most preferably100% pure by weight of the total polypeptide material present in thepreparation. The polypeptides of the present invention are preferably ina substantially pure form, i.e., that the polypeptide preparation isessentially free of other polypeptide material with which it is nativelyor recombinantly associated. This can be accomplished, for example, bypreparing the polypeptide by well-known recombinant methods or byclassical purification methods.

Mature polypeptide: The term “mature polypeptide” is defined herein as apolypeptide in its final form following translation and anypost-translational modifications, such as N-terminal processing,C-terminal truncation, glycosylation, phosphorylation, etc. In oneaspect, the mature polypeptide is amino acids 22 to 354 of SEQ ID NO: 2based on the SignalP program (Nielsen et al., 1997, Protein Engineering10:1-6) that predicts amino acids 1 to 21 of SEQ ID NO: 2 are a signalpeptide.

Mature polypeptide coding sequence: The term “mature polypeptide codingsequence” is defined herein as a nucleotide sequence that encodes amature polypeptide having cellulolytic enhancing activity. In oneaspect, the mature polypeptide coding sequence is nucleotides 64 to 1112of SEQ ID NO: 1 based on the SignalP program (Nielsen et al., 1997,supra) that predicts nucleotides 1 to 63 of SEQ ID NO: 1 encode a signalpeptide.

Identity: The relatedness between two amino acid sequences or betweentwo nucleotide sequences is described by the parameter “identity”.

For purposes of the present invention, the degree of sequence identitybetween two amino acid sequences is determined using theNeedleman-Wunsch algorithm (Needleman and Wunsch, 1970, J. Mol. Biol.48: 443-453) as implemented in the Needle program of the EMBOSS package(EMBOSS: The European Molecular Biology Open Software Suite, Rice etal., 2000, Trends in Genetics 16: 276-277), preferably version 3.0.0 orlater. The optional parameters used are gap open penalty of 10, gapextension penalty of 0.5, and the EBLOSUM62 (EMBOSS version of BLOSUM62)substitution matrix. The output of Needle labeled “longest identity”(obtained using the -nobrief option) is used as the percent identity andis calculated as follows:(Identical Residues×100)/(Length of Alignment−Total Number of Gaps inAlignment)

For purposes of the present invention, the degree of sequence identitybetween two deoxyribonucleotide sequences is determined using theNeedleman-Wunsch algorithm (Needleman and Wunsch, 1970, supra) asimplemented in the Needle program of the EMBOSS package (EMBOSS: TheEuropean Molecular Biology Open Software Suite, Rice et al., 2000,supra), preferably version 3.0.0 or later. The optional parameters usedare gap open penalty of 10, gap extension penalty of 0.5, and theEDNAFULL (EMBOSS version of NCBI NUC4.4) substitution matrix. The outputof Needle labeled “longest identity” (obtained using the -nobriefoption) is used as the percent identity and is calculated as follows:(Identical Deoxyribonucleotides×100)/(Length of Alignment−Total Numberof Gaps in Alignment)

Homologous sequence: The term “homologous sequence” is defined herein asa predicted protein having an E value (or expectancy score) of less than0.001 in a tfasty search (Pearson, W. R., 1999, in BioinformaticsMethods and Protocols, S. Misener and S. A. Krawetz, ed., pp. 185-219)with the Thermoascus aurantiacus polypeptide having cellulolyticenhancing activity of SEQ ID NO: 2 or the mature polypeptide thereof.

Polypeptide fragment: The term “polypeptide fragment” is defined hereinas a polypeptide having one or more (several) amino acids deleted fromthe amino and/or carboxyl terminus of the mature polypeptide of SEQ IDNO: 2; or a homologous sequence thereof; wherein the fragment hascellulolytic enhancing activity. In a preferred aspect, the fragmentcontains at least 285 amino acid residues, more preferably at least 300amino acid residues, and most preferably at least 315 amino acidresidues of the mature polypeptide of SEQ ID NO: 2 or a homologoussequence thereof. In another preferred aspect, the fragment isapproximately 25 kDa.

Subsequence: The term “subsequence” is defined herein as a nucleotidesequence having one or more (several) nucleotides deleted from the 5′and/or 3′ end of the mature polypeptide coding sequence of SEQ ID NO: 1;or a homologous sequence thereof; wherein the subsequence encodes apolypeptide fragment having cellulolytic enhancing activity. In apreferred aspect, the subsequence contains at least 855 nucleotides,more preferably at least 900 nucleotides, and most preferably at least945 nucleotides of the mature polypeptide coding sequence of SEQ ID NO:1 or a homologous sequence thereof.

Allelic variant: The term “allelic variant” denotes herein any of two ormore alternative forms of a gene occupying the same chromosomal locus.Allelic variation arises naturally through mutation, and may result inpolymorphism within populations. Gene mutations can be silent (no changein the encoded polypeptide) or may encode polypeptides having alteredamino acid sequences. An allelic variant of a polypeptide is apolypeptide encoded by an allelic variant of a gene.

Isolated polynucleotide: The term “isolated polynucleotide” as usedherein refers to a polynucleotide that is isolated from a source. In apreferred aspect, the polynucleotide is at least 1% pure, preferably atleast 5% pure, more preferably at least 10% pure, more preferably atleast 20% pure, more preferably at least 40% pure, more preferably atleast 60% pure, even more preferably at least 80% pure, and mostpreferably at least 90% pure, as determined by agarose electrophoresis.

Substantially pure polynucleotide: The term “substantially purepolynucleotide” as used herein refers to a polynucleotide preparationfree of other extraneous or unwanted nucleotides and in a form suitablefor use within genetically engineered protein production systems. Thus,a substantially pure polynucleotide contains at most 10%, preferably atmost 8%, more preferably at most 6%, more preferably at most 5%, morepreferably at most 4%, more preferably at most 3%, even more preferablyat most 2%, most preferably at most 1%, and even most preferably at most0.5% by weight of other polynucleotide material with which it isnatively or recombinantly associated. A substantially purepolynucleotide may, however, include naturally occurring 5′ and 3′untranslated regions, such as promoters and terminators. It is preferredthat the substantially pure polynucleotide is at least 90% pure,preferably at least 92% pure, more preferably at least 94% pure, morepreferably at least 95% pure, more preferably at least 96% pure, morepreferably at least 97% pure, even more preferably at least 98% pure,most preferably at least 99% pure, and even most preferably at least99.5% pure by weight. The polynucleotides of the present invention arepreferably in a substantially pure form, i.e., that the polynucleotidepreparation is essentially free of other polynucleotide material withwhich it is natively or recombinantly associated. The polynucleotidesmay be of genomic, cDNA, RNA, semisynthetic, synthetic origin, or anycombinations thereof.

Coding sequence: When used herein the term “coding sequence” means anucleotide sequence, which directly specifies the amino acid sequence ofits protein product. The boundaries of the coding sequence are generallydetermined by an open reading frame, which usually begins with the ATGstart codon or alternative start codons such as GTG and TTG and endswith a stop codon such as TAA, TAG, and TGA. The coding sequence may bea DNA, cDNA, synthetic, or recombinant nucleotide sequence.

cDNA: The term “cDNA” is defined herein as a DNA molecule that can beprepared by reverse transcription from a mature, spliced, mRNA moleculeobtained from a eukaryotic cell. cDNA lacks intron sequences that may bepresent in the corresponding genomic DNA. The initial, primary RNAtranscript is a precursor to mRNA that is processed through a series ofsteps before appearing as mature spliced mRNA. These steps include theremoval of intron sequences by a process called splicing. cDNA derivedfrom mRNA lacks, therefore, any intron sequences.

Nucleic acid construct: The term “nucleic acid construct” as used hereinrefers to a nucleic acid molecule, either single- or double-stranded,which is isolated from a naturally occurring gene or which is modifiedto contain segments of nucleic acids in a manner that would nototherwise exist in nature or which is synthetic. The term nucleic acidconstruct is synonymous with the term “expression cassette” when thenucleic acid construct contains the control sequences required forexpression of a coding sequence of the present invention.

Control sequences: The term “control sequences” is defined herein toinclude all components necessary for the expression of a polynucleotideencoding a polypeptide of the present invention. Each control sequencemay be native or foreign to the nucleotide sequence encoding thepolypeptide or native or foreign to each other. Such control sequencesinclude, but are not limited to, a leader, polyadenylation sequence,propeptide sequence, promoter, signal peptide sequence, andtranscription terminator. At a minimum, the control sequences include apromoter, and transcriptional and translational stop signals. Thecontrol sequences may be provided with linkers for the purpose ofintroducing specific restriction sites facilitating ligation of thecontrol sequences with the coding region of the nucleotide sequenceencoding a polypeptide.

Operably linked: The term “operably linked” denotes herein aconfiguration in which a control sequence is placed at an appropriateposition relative to the coding sequence of a polynucleotide sequencesuch that the control sequence directs the expression of the codingsequence of a polypeptide.

Expression: The term “expression” includes any step involved in theproduction of a polypeptide including, but not limited to,transcription, post-transcriptional modification, translation,post-translational modification, and secretion.

Expression vector: The term “expression vector” is defined herein as alinear or circular DNA molecule that comprises a polynucleotide encodinga polypeptide of the present invention and is operably linked toadditional nucleotides that provide for its expression.

Host cell: The term “host cell”, as used herein, includes any cell typethat is susceptible to transformation, transfection, transduction, andthe like with a nucleic acid construct or expression vector comprising apolynucleotide of the present invention.

Modification: The term “modification” means herein any chemicalmodification of the polypeptide comprising or consisting of the maturepolypeptide of SEQ ID NO: 2; or a homologous sequence thereof; as wellas genetic manipulation of the DNA encoding such a polypeptide. Themodification can be a substitution, a deletion and/or an insertion ofone or more (several) amino acids as well as replacements of one or more(several) amino acid side chains.

Artificial variant: When used herein, the term “artificial variant”means a polypeptide having cellulolytic enhancing activity produced byan organism expressing a modified polynucleotide sequence of the maturepolypeptide coding sequence of SEQ ID NO: 1; or a homologous sequencethereof. The modified nucleotide sequence is obtained through humanintervention by modification of the polynucleotide sequence disclosed inSEQ ID NO: 1; or a homologous sequence thereof.

DETAILED DESCRIPTION OF THE INVENTION Polypeptides Having CellulolyticEnhancing Activity

In a first aspect, the present invention relates to isolatedpolypeptides comprising amino acid sequences having a degree of sequenceidentity to the mature polypeptide of SEQ ID NO: 2 of preferably atleast 80%, more preferably at least 85%, even more preferably at least90%, most preferably at least 95%, and even most preferably at least96%, at least 97%, at least 98%, or at least 99%, which havecellulolytic enhancing activity (hereinafter “homologous polypeptides”).In a preferred aspect, the homologous polypeptides comprise amino acidsequences that differ by ten amino acids, preferably by five aminoacids, more preferably by four amino acids, even more preferably bythree amino acids, most preferably by two amino acids, and even mostpreferably by one amino acid from the mature polypeptide of SEQ ID NO:2.

A polypeptide of the present invention preferably comprises the aminoacid sequence of SEQ ID NO: 2 or an allelic variant thereof; or afragment thereof having cellulolytic enhancing activity. In a preferredaspect, the polypeptide comprises the amino acid sequence of SEQ ID NO:2. In another preferred aspect, the polypeptide comprises the maturepolypeptide of SEQ ID NO: 2. In another preferred aspect, thepolypeptide comprises amino acids 22 to 354 of SEQ ID NO: 2, or anallelic variant thereof; or a fragment thereof having cellulolyticenhancing activity. In another preferred aspect, the polypeptidecomprises amino acids 22 to 354 of SEQ ID NO: 2. In another preferredaspect, the polypeptide consists of the amino acid sequence of SEQ IDNO: 2 or an allelic variant thereof; or a fragment thereof havingcellulolytic enhancing activity. In another preferred aspect, thepolypeptide consists of the amino acid sequence of SEQ ID NO: 2. Inanother preferred aspect, the polypeptide consists of the maturepolypeptide of SEQ ID NO: 2. In another preferred aspect, thepolypeptide consists of amino acids 22 to 354 of SEQ ID NO: 2 or anallelic variant thereof; or a fragment thereof having cellulolyticenhancing activity. In another preferred aspect, the polypeptideconsists of amino acids 22 to 354 of SEQ ID NO: 2.

In a second aspect, the present invention relates to isolatedpolypeptides having cellulolytic enhancing activity that are encoded bypolynucleotides that hybridize under preferably very low stringencyconditions, more preferably low stringency conditions, more preferablymedium stringency conditions, more preferably medium-high stringencyconditions, even more preferably high stringency conditions, and mostpreferably very high stringency conditions with (i) the maturepolypeptide coding sequence of SEQ ID NO: 1, (ii) the cDNA sequencecontained in the mature polypeptide coding sequence of SEQ ID NO: 1, or(iii) a full-length complementary strand of (i) or (ii) (J. Sambrook, E.F. Fritsch, and T. Maniatis, 1989, Molecular Cloning, A LaboratoryManual, 2d edition, Cold Spring Harbor, N.Y.).

The nucleotide sequence of SEQ ID NO: 1; or a subsequence thereof; aswell as the amino acid sequence of SEQ ID NO: 2; or a fragment thereof;may be used to design nucleic acid probes to identify and clone DNAencoding polypeptides having cellulolytic enhancing activity fromstrains of different genera or species according to methods well knownin the art. In particular, such probes can be used for hybridizationwith the genomic or cDNA of the genus or species of interest, followingstandard Southern blotting procedures, in order to identify and isolatethe corresponding gene therein. Such probes can be considerably shorterthan the entire sequence, but should be at least 14, preferably at least25, more preferably at least 35, and most preferably at least 70nucleotides in length. It is, however, preferred that the nucleic acidprobe is at least 100 nucleotides in length. For example, the nucleicacid probe may be at least 200 nucleotides, preferably at least 300nucleotides, more preferably at least 400 nucleotides, or mostpreferably at least 500 nucleotides in length. Both DNA and RNA probescan be used. The probes are typically labeled for detecting thecorresponding gene (for example, with ³²P, ³H, ³⁵S, biotin, or avidin).Such probes are encompassed by the present invention.

A genomic DNA or cDNA library prepared from such other strains may,therefore, be screened for DNA that hybridizes with the probes describedabove and encodes a polypeptide having cellulolytic enhancing activity.Genomic or other DNA from such other strains may be separated by agaroseor polyacrylamide gel electrophoresis, or other separation techniques.DNA from the libraries or the separated DNA may be transferred to andimmobilized on nitrocellulose or other suitable carrier material. Inorder to identify a clone or DNA that is homologous with SEQ ID NO: 1,or a subsequence thereof, the carrier material is preferably used in aSouthern blot.

For purposes of the present invention, hybridization indicates that thenucleotide sequence hybridizes to a labeled nucleic acid probecorresponding to the mature polypeptide coding sequence of SEQ ID NO: 1;the cDNA sequence contained in the mature polypeptide coding sequence ofSEQ ID NO: 1; its full-length complementary strand; or a subsequencethereof; under very low to very high stringency conditions. Molecules towhich the nucleic acid probe hybridizes under these conditions can bedetected using, for example, X-ray film.

In a preferred aspect, the nucleic acid probe is the mature polypeptidecoding sequence of SEQ ID NO: 1. In another preferred aspect, thenucleic acid probe is nucleotides 64 to 1112 of SEQ ID NO: 1. In anotherpreferred aspect, the nucleic acid probe is a polynucleotide sequencethat encodes the polypeptide of SEQ ID NO: 2, or a subsequence thereof.In another preferred aspect, the nucleic acid probe is SEQ ID NO: 1. Inanother preferred aspect, the nucleic acid probe is the polynucleotidesequence contained in plasmid pXYZ1473 which is contained in E. coli DSM22075, wherein the polynucleotide sequence thereof encodes a polypeptidehaving cellulolytic enhancing activity. In another preferred aspect, thenucleic acid probe is the mature polypeptide coding region contained inplasmid pXYZ1473 which is contained in E. coli DSM 22075.

For long probes of at least 100 nucleotides in length, very low to veryhigh stringency conditions are defined as prehybridization andhybridization at 42° C. in 5×SSPE, 0.3% SDS, 200 μg/ml sheared anddenatured salmon sperm DNA, and either 25% formamide for very low andlow stringencies, 35% formamide for medium and medium-high stringencies,or 50% formamide for high and very high stringencies, following standardSouthern blotting procedures for 12 to 24 hours optimally.

For long probes of at least 100 nucleotides in length, the carriermaterial is finally washed three times each for 15 minutes using 2×SSC,0.2% SDS preferably at 45° C. (very low stringency), more preferably at50° C. (low stringency), more preferably at 55° C. (medium stringency),more preferably at 60° C. (medium-high stringency), even more preferablyat 65° C. (high stringency), and most preferably at 70° C. (very highstringency).

For short probes of about 15 nucleotides to about 70 nucleotides inlength, stringency conditions are defined as prehybridization,hybridization, and washing post-hybridization at about 5° C. to about10° C. below the calculated T_(m) using the calculation according toBolton and McCarthy (1962, Proceedings of the National Academy ofSciences USA 48:1390) in 0.9 M NaCl, 0.09 M Tris-HCl pH 7.6, 6 mM EDTA,0.5% NP-40, 1×Denhardt's solution, 1 mM sodium pyrophosphate, 1 mMsodium monobasic phosphate, 0.1 mM ATP, and 0.2 mg of yeast RNA per mlfollowing standard Southern blotting procedures for 12 to 24 hoursoptimally.

For short probes of about 15 nucleotides to about 70 nucleotides inlength, the carrier material is washed once in 6×SCC plus 0.1% SDS for15 minutes and twice each for 15 minutes using 6×SSC at 5° C. to 10° C.below the calculated T_(m).

In a third aspect, the present invention relates to isolatedpolypeptides having cellulolytic enhancing activity encoded bypolynucleotides comprising or consisting of nucleotide sequences thathave a degree of sequence identity to the mature polypeptide codingsequence of SEQ ID NO: 1 of preferably at least 80%, more preferably atleast 85%, even more preferably at least 90%, most preferably at least95%, and even most preferably at least 96%, at least 97%, at least 98%,or at least 99%, which encode a polypeptide having cellulolyticenhancing activity. See polynucleotide section herein.

In a fourth aspect, the present invention relates to artificial variantscomprising a substitution, deletion, and/or insertion of one or more (orseveral) amino acids of the mature polypeptide of SEQ ID NO: 2, or ahomologous sequence thereof. Preferably, amino acid changes are of aminor nature, that is conservative amino acid substitutions orinsertions that do not significantly affect the folding and/or activityof the protein; small deletions, typically of one to about 30 aminoacids; small amino- or carboxyl-terminal extensions, such as anamino-terminal methionine residue; a small linker peptide of up to about20-25 residues; or a small extension that facilitates purification bychanging net charge or another function, such as a poly-histidine tract,an antigenic epitope or a binding domain.

Examples of conservative substitutions are within the group of basicamino acids (arginine, lysine and histidine), acidic amino acids(glutamic acid and aspartic acid), polar amino acids (glutamine andasparagine), hydrophobic amino acids (leucine, isoleucine and valine),aromatic amino acids (phenylalanine, tryptophan and tyrosine), and smallamino acids (glycine, alanine, serine, threonine and methionine). Aminoacid substitutions that do not generally alter specific activity areknown in the art and are described, for example, by H. Neurath and R. L.Hill, 1979, In, The Proteins, Academic Press, New York. The mostcommonly occurring exchanges are Ala/Ser, Val/Ile, Asp/Glu, Thr/Ser,Ala/Gly, Ala/Thr, Ser/Asn, Ala/Val, Ser/Gly, Tyr/Phe, Ala/Pro, Lys/Arg,Asp/Asn, Leu/Ile, Leu/Val, Ala/Glu, and Asp/Gly.

In addition to the 20 standard amino acids, non-standard amino acids(such as 4-hydroxyproline, 6-N-methyl lysine, 2-aminoisobutyric acid,isovaline, and alpha-methyl serine) may be substituted for amino acidresidues of a wild-type polypeptide. A limited number ofnon-conservative amino acids, amino acids that are not encoded by thegenetic code, and unnatural amino acids may be substituted for aminoacid residues. “Unnatural amino acids” have been modified after proteinsynthesis, and/or have a chemical structure in their side chain(s)different from that of the standard amino acids. Unnatural amino acidscan be chemically synthesized, and preferably, are commerciallyavailable, and include pipecolic acid, thiazolidine carboxylic acid,dehydroproline, 3- and 4-methylproline, and 3,3-dimethylproline.

Alternatively, the amino acid changes are of such a nature that thephysico-chemical properties of the polypeptides are altered. Forexample, amino acid changes may improve the thermal stability of thepolypeptide, alter the substrate specificity, change the pH optimum, andthe like.

Essential amino acids in the parent polypeptide can be identifiedaccording to procedures known in the art, such as site-directedmutagenesis or alanine-scanning mutagenesis (Cunningham and Wells, 1989,Science 244: 1081-1085). In the latter technique, single alaninemutations are introduced at every residue in the molecule, and theresultant mutant molecules are tested for biological activity (i.e.,cellulolytic enhancing activity) to identify amino acid residues thatare critical to the activity of the molecule. See also, Hilton et al.,1996, J. Biol. Chem. 271: 4699-4708. The active site of the enzyme orother biological interaction can also be determined by physical analysisof structure, as determined by such techniques as nuclear magneticresonance, crystallography, electron diffraction, or photoaffinitylabeling, in conjunction with mutation of putative contact site aminoacids. See, for example, de Vos et al., 1992, Science 255: 306-312;Smith et al., 1992, J. Mol. Biol. 224: 899-904; Wlodaver et al., 1992,FEBS Lett. 309: 59-64. The identities of essential amino acids can alsobe inferred from analysis of identities with polypeptides that arerelated to a polypeptide according to the invention.

Single or multiple amino acid substitutions, deletions, and/orinsertions can be made and tested using known methods of mutagenesis,recombination, and/or shuffling, followed by a relevant screeningprocedure, such as those disclosed by Reidhaar-Olson and Sauer, 1988,Science 241: 53-57; Bowie and Sauer, 1989, Proc. Natl. Acad. Sci. USA86: 2152-2156; WO 95/17413; or WO 95/22625. Other methods that can beused include error-prone PCR, phage display (e.g., Lowman et al., 1991,Biochem. 30: 10832-10837; U.S. Pat. No. 5,223,409; WO 92/06204), andregion-directed mutagenesis (Derbyshire et al., 1986, Gene 46: 145; Neret al., 1988, DNA 7: 127).

Mutagenesis/shuffling methods can be combined with high-throughput,automated screening methods to detect activity of cloned, mutagenizedpolypeptides expressed by host cells (Ness et al., 1999, NatureBiotechnology 17: 893-896). Mutagenized DNA molecules that encode activepolypeptides can be recovered from the host cells and rapidly sequencedusing standard methods in the art. These methods allow the rapiddetermination of the importance of individual amino acid residues in apolypeptide of interest, and can be applied to polypeptides of unknownstructure.

The total number of amino acid substitutions, deletions and/orinsertions of the mature polypeptide of SEQ ID NO: 2 is 10, preferably9, more preferably 8, more preferably 7, more preferably at most 6, morepreferably 5, more preferably 4, even more preferably 3, most preferably2, and even most preferably 1.

Sources of Polypeptides Having Cellulolytic Enhancing Activity

A polypeptide having cellulolytic enhancing activity of the presentinvention may be obtained from microorganisms of any genus. For purposesof the present invention, the term “obtained from” as used herein inconnection with a given source shall mean that the polypeptide encodedby a nucleotide sequence is produced by the source or by a strain inwhich the nucleotide sequence from the source has been inserted. In apreferred aspect, the polypeptide obtained from a given source issecreted extracellularly.

A polypeptide having cellulolytic enhancing activity of the presentinvention may be a bacterial polypeptide. For example, the polypeptidemay be a gram positive bacterial polypeptide such as a Bacillus,Streptococcus, Streptomyces, Staphylococcus, Enterococcus,Lactobacillus, Lactococcus, Clostridium, Geobacillus, or Oceanobacilluspolypeptide having cellulolytic enhancing activity, or a Gram negativebacterial polypeptide such as an E. coli, Pseudomonas, Salmonella,Campylobacter, Helicobacter, Flavobacterium, Fusobacterium, Ilyobacter,Neisseria, or Ureaplasma polypeptide having cellulolytic enhancingactivity.

In a preferred aspect, the polypeptide is a Bacillus alkalophilus,Bacillus amyloliquefaciens, Bacillus brevis, Bacillus circulans,Bacillus clausii, Bacillus coagulans, Bacillus firmus, Bacillus lautus,Bacillus lentus, Bacillus licheniformis, Bacillus megaterium, Bacilluspumilus, Bacillus stearothermophilus, Bacillus subtilis, or Bacillusthuringiensis polypeptide having cellulolytic enhancing activity.

In another preferred aspect, the polypeptide is a Streptococcusequisimilis, Streptococcus pyogenes, Streptococcus uberis, orStreptococcus equi subsp. Zooepidemicus polypeptide having cellulolyticenhancing activity.

In another preferred aspect, the polypeptide is a Streptomycesachromogenes, Streptomyces avermitilis, Streptomyces coelicolor,Streptomyces griseus, or Streptomyces lividans polypeptide havingcellulolytic enhancing activity.

A polypeptide having cellulolytic enhancing activity of the presentinvention may also be a fungal polypeptide, and more preferably a yeastpolypeptide such as a Candida, Kluyveromyces, Pichia, Saccharomyces,Schizosaccharomyces, or Yarrowia polypeptide having cellulolyticenhancing activity; or more preferably a filamentous fungal polypeptidesuch as an Acremonium, Agaricus, Alternaria, Aspergillus, Aureobasidium,Botryospaeria, Ceriporiopsis, Chaetomidium, Chrysosporium, Claviceps,Cochliobolus, Coprinopsis, Coptotermes, Corynascus, Cryphonectria,Cryptococcus, Diplodia, Exidia, Filibasidium, Fusarium, Gibberella,Holomastigotoides, Humicola, Irpex, Lentinula, Leptospaeria,Magnaporthe, Melanocarpus, Meripilus, Mucor, Myceliophthora,Neocallimastix, Neurospora, Paecilomyces, Penicillium, Phanerochaete,Piromyces, Poitrasia, Pseudoplectania, Pseudotrichonympha, Rhizomucor,Schizophyllum, Scytalidium, Talaromyces, Thermoascus, Thielavia,Tolypocladium, Trichoderma, Trichophaea, Verticillium, Volvariella, orXylaria polypeptide having cellulolytic enhancing activity.

In a preferred aspect, the polypeptide is a Saccharomycescarlsbergensis, Saccharomyces cerevisiae, Saccharomyces diastaticus,Saccharomyces douglasii, Saccharomyces kluyveri, Saccharomycesnorbensis, or Saccharomyces oviformis polypeptide having cellulolyticenhancing activity.

In another preferred aspect, the polypeptide is an Acremoniumcellulolyticus, Aspergillus aculeatus, Aspergillus awamori, Aspergillusfumigatus, Aspergillus foetidus, Aspergillus japonicus, Aspergillusnidulans, Aspergillus niger, Aspergillus oryzae, Chrysosporiumkeratinophilum, Chrysosporium lucknowense, Chrysosporium tropicum,Chrysosporium merdarium, Chrysosporium inops, Chrysosporium pannicola,Chrysosporium queenslandicum, Chrysosporium zonatum, Fusariumbactridioides, Fusarium cerealis, Fusarium crookwellense, Fusariumculmorum, Fusarium graminearum, Fusarium graminum, Fusariumheterosporum, Fusarium negundi, Fusarium oxysporum, Fusariumreticulatum, Fusarium roseum, Fusarium sambucinum, Fusarium sarcochroum,Fusarium sporotrichioides, Fusarium sulphureum, Fusarium torulosum,Fusarium trichothecioides, Fusarium venenatum, Humicola grisea, Humicolainsolens, Humicola lanuginosa, Irpex lacteus, Mucor miehei,Myceliophthora thermophila, Neurospora crassa, Penicillium funiculosum,Penicillium purpurogenum, Phanerochaete chrysosporium, Thielaviaachromatica, Thielavia albomyces, Thielavia albopilosa, Thielaviaaustraleinsis, Thielavia fimeti, Thielavia microspora, Thielaviaovispora, Thielavia peruviana, Thielavia spededonium, Thielavia setosa,Thielavia subthermophila, Thielavia terrestris, Trichoderma harzianum,Trichoderma koningii, Trichoderma longibrachiatum, Trichoderma reesei,or Trichoderma viride polypeptide having cellulolytic enhancingactivity.

In a more preferred aspect, the polypeptide is a Thermoascus aurantiacuspolypeptide having cellulolytic enhancing activity. In a most preferredaspect, the polypeptide is a Thermoascus aurantiacus CGMCC 0670polypeptide having cellulolytic enhancing activity, e.g., thepolypeptide comprising the mature polypeptide of SEQ ID NO: 2.

It will be understood that for the aforementioned species the inventionencompasses both the perfect and imperfect states, and other taxonomicequivalents, e.g., anamorphs, regardless of the species name by whichthey are known. Those skilled in the art will readily recognize theidentity of appropriate equivalents.

Strains of these species are readily accessible to the public in anumber of culture collections, such as the American Type CultureCollection (ATCC), Deutsche Sammlung von Mikroorganismen andZellkulturen GmbH (DSM), Centraalbureau Voor Schimmelcultures (CBS), andAgricultural Research Service Patent Culture Collection, NorthernRegional Research Center (NRRL).

Furthermore, such polypeptides may be identified and obtained from othersources including microorganisms isolated from nature (e.g., soil,composts, water, etc.) using the above-mentioned probes. Techniques forisolating microorganisms from natural habitats are well known in theart. The polynucleotide may then be obtained by similarly screening agenomic or cDNA library of such a microorganism. Once a polynucleotideencoding a polypeptide has been detected with the probe(s), thepolynucleotide can be isolated or cloned by utilizing techniques thatare well known to those of ordinary skill in the art (see, e.g.,Sambrook et al., 1989, supra).

Polypeptides of the present invention also include fused polypeptides orcleavable fusion polypeptides in which another polypeptide is fused atthe N-terminus or the C-terminus of the polypeptide or fragment thereof.A fused polypeptide is produced by fusing a nucleotide sequence (or aportion thereof) encoding another polypeptide to a nucleotide sequence(or a portion thereof) of the present invention. Techniques forproducing fusion polypeptides are known in the art, and include ligatingthe coding sequences encoding the polypeptides so that they are in frameand that expression of the fused polypeptide is under control of thesame promoter(s) and terminator.

A fusion polypeptide can further comprise a cleavage site. Uponsecretion of the fusion protein, the site is cleaved releasing thepolypeptide having cellulolytic enhancing activity from the fusionprotein. Examples of cleavage sites include, but are not limited to, aKex2 site that encodes the dipeptide Lys-Arg (Martin et al., 2003, J.Ind. Microbiol. Biotechnol. 3: 568-576; Svetina et al., 2000, J.Biotechnol. 76: 245-251; Rasmussen-Wilson et al., 1997, Appl. Environ.Microbiol. 63: 3488-3493; Ward et al., 1995, Biotechnology 13: 498-503;and Contreras et al., 1991, Biotechnology 9: 378-381), an Ile-(Glu orAsp)-Gly-Arg site, which is cleaved by a Factor Xa protease after thearginine residue (Eaton et al., 1986, Biochem. 25: 505-512); aAsp-Asp-Asp-Asp-Lys site, which is cleaved by an enterokinase after thelysine (Collins-Racie et al., 1995, Biotechnology 13: 982-987); aHis-Tyr-Glu site or His-Tyr-Asp site, which is cleaved by Genenase I(Carter et al., 1989, Proteins: Structure, Function, and Genetics 6:240-248); a Leu-Val-Pro-Arg-Gly-Ser site, which is cleaved by thrombinafter the Arg (Stevens, 2003, Drug Discovery World 4: 35-48); aGlu-Asn-Leu-Tyr-Phe-Gln-Gly site, which is cleaved by TEV protease afterthe Gln (Stevens, 2003, supra); and a Leu-Glu-Val-Leu-Phe-Gln-Gly-Prosite, which is cleaved by a genetically engineered form of humanrhinovirus 3C protease after the Gln (Stevens, 2003, supra).

Polynucleotides

The present invention also relates to isolated polynucleotidescomprising or consisting of nucleotide sequences that encodepolypeptides having cellulolytic enhancing activity of the presentinvention.

In a preferred aspect, the nucleotide sequence comprises or consists ofSEQ ID NO: 1. In another more preferred aspect, the nucleotide sequencecomprises or consists of the sequence contained in plasmid pXYZ1473which is contained in E. coli DSM 22075. In another preferred aspect,the nucleotide sequence comprises or consists of the mature polypeptidecoding sequence of SEQ ID NO: 1. In another preferred aspect, thenucleotide sequence comprises or consists of nucleotides 64 to 1112 ofSEQ ID NO: 1. In another more preferred aspect, the nucleotide sequencecomprises or consists of the mature polypeptide coding sequencecontained in plasmid pXYZ1473 which is contained in E. coli DSM 22075.The present invention also encompasses nucleotide sequences that encodepolypeptides comprising or consisting of the amino acid sequence of SEQID NO: 2 or the mature polypeptide thereof, which differ from SEQ ID NO:1 or the mature polypeptide coding sequence thereof by virtue of thedegeneracy of the genetic code. The present invention also relates tosubsequences of SEQ ID NO: 1 that encode fragments of SEQ ID NO: 2 thathave cellulolytic enhancing activity.

The present invention also relates to mutant polynucleotides comprisingor consisting of at least one mutation in the mature polypeptide codingsequence of SEQ ID NO: 1, in which the mutant nucleotide sequenceencodes the mature polypeptide of SEQ ID NO: 2.

The techniques used to isolate or clone a polynucleotide encoding apolypeptide are known in the art and include isolation from genomic DNA,preparation from cDNA, or a combination thereof. The cloning of thepolynucleotides of the present invention from such genomic DNA can beeffected, e.g., by using the well known polymerase chain reaction (PCR)or antibody screening of expression libraries to detect cloned DNAfragments with shared structural features. See, e.g., Innis et al.,1990, PCR: A Guide to Methods and Application, Academic Press, New York.Other nucleic acid amplification procedures such as ligase chainreaction (LCR), ligated activated transcription (LAT) and nucleotidesequence-based amplification (NASBA) may be used. The polynucleotidesmay be cloned from a strain of Thermoascus, or another or relatedorganism and thus, for example, may be an allelic or species variant ofthe polypeptide encoding region of the nucleotide sequence.

The present invention also relates to isolated polynucleotidescomprising or consisting of nucleotide sequences that have a degree ofsequence identity to the mature polypeptide coding sequence of SEQ IDNO: 1 of preferably at least 80%, more preferably at least 85%, evenmore preferably at least 90%, most preferably at least 95%, and evenmost preferably at least 96%, at least 97%, at least 98%, or at least99%, which encode a polypeptide having cellulolytic enhancing activity.

Modification of a nucleotide sequence encoding a polypeptide of thepresent invention may be necessary for the synthesis of polypeptidessubstantially similar to the polypeptide. The term “substantiallysimilar” to the polypeptide refers to non-naturally occurring forms ofthe polypeptide. These polypeptides may differ in some engineered wayfrom the polypeptide isolated from its native source, e.g., artificialvariants that differ in specific activity, thermostability, pH optimum,or the like. The variant sequence may be constructed on the basis of thenucleotide sequence presented as the mature polypeptide coding sequenceof SEQ ID NO: 1, e.g., a subsequence thereof, and/or by introduction ofnucleotide substitutions that do not give rise to another amino acidsequence of the polypeptide encoded by the nucleotide sequence, butwhich correspond to the codon usage of the host organism intended forproduction of the enzyme, or by introduction of nucleotide substitutionsthat may give rise to a different amino acid sequence. For a generaldescription of nucleotide substitution, see, e.g., Ford et al., 1991,Protein Expression and Purification 2: 95-107.

It will be apparent to those skilled in the art that such substitutionscan be made outside the regions critical to the function of the moleculeand still result in an active polypeptide. Amino acid residues essentialto the activity of the polypeptide encoded by an isolated polynucleotideof the invention, and therefore preferably not subject to substitution,may be identified according to procedures known in the art, such assite-directed mutagenesis or alanine-scanning mutagenesis (see, e.g.,Cunningham and Wells, 1989, supra). In the latter technique, mutationsare introduced at every positively charged residue in the molecule, andthe resultant mutant molecules are tested for cellulolytic enhancingactivity to identify amino acid residues that are critical to theactivity of the molecule. Sites of substrate-enzyme interaction can alsobe determined by analysis of the three-dimensional structure asdetermined by such techniques as nuclear magnetic resonance analysis,crystallography or photoaffinity labeling (see, e.g., de Vos et al.,1992, supra; Smith et al., 1992, supra; Wlodaver et al., 1992, supra).

The present invention also relates to isolated polynucleotides encodingpolypeptides of the present invention, which hybridize under very lowstringency conditions, preferably low stringency conditions, morepreferably medium stringency conditions, more preferably medium-highstringency conditions, even more preferably high stringency conditions,and most preferably very high stringency conditions with (i) the maturepolypeptide coding sequence of SEQ ID NO: 1, (ii) the cDNA sequencecontained in the mature polypeptide coding sequence of SEQ ID NO: 1, or(iii) a full-length complementary strand of (i) or (ii); or allelicvariants and subsequences thereof (Sambrook et al., 1989, supra), asdefined herein. In a preferred aspect, the complementary strand is thefull-length complementary strand of the mature polypeptide codingsequence of SEQ ID NO: 1.

The present invention also relates to isolated polynucleotides obtainedby (a) hybridizing a population of DNA under very low, low, medium,medium-high, high, or very high stringency conditions with (i) themature polypeptide coding sequence of SEQ ID NO: 1, (ii) the cDNAsequence contained in the mature polypeptide coding sequence of SEQ IDNO: 1, or (iii) a full-length complementary strand of (i) or (ii); and(b) isolating the hybridizing polynucleotide, which encodes apolypeptide having cellulolytic enhancing activity. In a preferredaspect, the complementary strand is the full-length complementary strandof the mature polypeptide coding sequence of SEQ ID NO: 1.

Nucleic Acid Constructs

The present invention also relates to nucleic acid constructs comprisingan isolated polynucleotide of the present invention operably linked toone or more (several) control sequences that direct the expression ofthe coding sequence in a suitable host cell under conditions compatiblewith the control sequences.

An isolated polynucleotide encoding a polypeptide of the presentinvention may be manipulated in a variety of ways to provide forexpression of the polypeptide. Manipulation of the polynucleotide'ssequence prior to its insertion into a vector may be desirable ornecessary depending on the expression vector. The techniques formodifying polynucleotide sequences utilizing recombinant DNA methods arewell known in the art.

The control sequence may be an appropriate promoter sequence, anucleotide sequence that is recognized by a host cell for expression ofa polynucleotide encoding a polypeptide of the present invention. Thepromoter sequence contains transcriptional control sequences thatmediate the expression of the polypeptide. The promoter may be anynucleotide sequence that shows transcriptional activity in the host cellof choice including mutant, truncated, and hybrid promoters, and may beobtained from genes encoding extracellular or intracellular polypeptideseither homologous or heterologous to the host cell.

Examples of suitable promoters for directing the transcription of thenucleic acid constructs of the present invention, especially in abacterial host cell, are the promoters obtained from the E. coli lacoperon, Streptomyces coelicolor agarase gene (dagA), Bacillus subtilislevansucrase gene (sacB), Bacillus licheniformis alpha-amylase gene(amyL), Bacillus stearothermophilus maltogenic amylase gene (amyM),Bacillus amyloliquefaciens alpha-amylase gene (amyQ), Bacilluslicheniformis penicillinase gene (penP), Bacillus subtilis xylA and xylBgenes, and prokaryotic beta-lactamase gene (Villa-Kamaroff et al., 1978,Proceedings of the National Academy of Sciences USA 75: 3727-3731), aswell as the tac promoter (DeBoer et al., 1983, Proceedings of theNational Academy of Sciences USA 80: 21-25). Further promoters aredescribed in “Useful proteins from recombinant bacteria” in ScientificAmerican, 1980, 242: 74-94; and in Sambrook et al., 1989, supra.

Examples of suitable promoters for directing the transcription of thenucleic acid constructs of the present invention in a filamentous fungalhost cell are promoters obtained from the genes for Aspergillus oryzaeTAKA amylase, Rhizomucor miehei aspartic proteinase, Aspergillus nigerneutral alpha-amylase, Aspergillus niger acid stable alpha-amylase,Aspergillus niger or Aspergillus awamori glucoamylase (glaA), Rhizomucormiehei lipase, Aspergillus oryzae alkaline protease, Aspergillus oryzaetriose phosphate isomerase, Aspergillus nidulans acetamidase, Fusariumvenenatum amyloglucosidase (WO 00/56900), Fusarium venenatum Daria (WO00/56900), Fusarium venenatum Quinn (WO 00/56900), Fusarium oxysporumtrypsin-like protease (WO 96/00787), Trichoderma reeseibeta-glucosidase, Trichoderma reesei cellobiohydrolase I, Trichodermareesei cellobiohydrolase II, Trichoderma reesei endoglucanase I,Trichoderma reesei endoglucanase II, Trichoderma reesei endoglucanaseIII, Trichoderma reesei endoglucanase IV, Trichoderma reeseiendoglucanase V, Trichoderma reesei xylanase I, Trichoderma reeseixylanase II, Trichoderma reesei beta-xylosidase, as well as the NA2-tpipromoter (a modified promoter including a gene encoding a neutralalpha-amylase in Aspergilli in which the untranslated leader has beenreplaced by an untranslated leader from a gene encoding triose phosphateisomerase in Aspergilli; non-limiting examples include modifiedpromoters including the gene encoding neutral alpha-amylase inAspergillus niger in which the untranslated leader has been replaced byan untranslated leader from the gene encoding triose phosphate isomerasein Aspergillus nidulans or Aspergillus oryzae); and mutant, truncated,and hybrid promoters thereof.

In a yeast host, useful promoters are obtained from the genes forSaccharomyces cerevisiae enolase (ENO-1), Saccharomyces cerevisiaegalactokinase (GAL1), Saccharomyces cerevisiae alcoholdehydrogenase/glyceraldehyde-3-phosphate dehydrogenase (ADH1, ADH2/GAP),Saccharomyces cerevisiae triose phosphate isomerase (TPI), Saccharomycescerevisiae metallothionein (CUP1), and Saccharomyces cerevisiae3-phosphoglycerate kinase. Other useful promoters for yeast host cellsare described by Romanos et al., 1992, Yeast 8: 423-488.

The control sequence may also be a suitable transcription terminatorsequence, a sequence recognized by a host cell to terminatetranscription. The terminator sequence is operably linked to the 3′terminus of the nucleotide sequence encoding the polypeptide. Anyterminator that is functional in the host cell of choice may be used inthe present invention.

Preferred terminators for filamentous fungal host cells are obtainedfrom the genes for Aspergillus oryzae TAKA amylase, Aspergillus nigerglucoamylase, Aspergillus nidulans anthranilate synthase, Aspergillusniger alpha-glucosidase, and Fusarium oxysporum trypsin-like protease.

Preferred terminators for yeast host cells are obtained from the genesfor Saccharomyces cerevisiae enolase, Saccharomyces cerevisiaecytochrome C (CYC1), and Saccharomyces cerevisiaeglyceraldehyde-3-phosphate dehydrogenase. Other useful terminators foryeast host cells are described by Romanos et al., 1992, supra.

The control sequence may also be a suitable leader sequence, anontranslated region of an mRNA that is important for translation by thehost cell. The leader sequence is operably linked to the 5′ terminus ofthe nucleotide sequence encoding the polypeptide. Any leader sequencethat is functional in the host cell of choice may be used in the presentinvention.

Preferred leaders for filamentous fungal host cells are obtained fromthe genes for Aspergillus oryzae TAKA amylase and Aspergillus nidulanstriose phosphate isomerase.

Suitable leaders for yeast host cells are obtained from the genes forSaccharomyces cerevisiae enolase (ENO-1), Saccharomyces cerevisiae3-phosphoglycerate kinase, Saccharomyces cerevisiae alpha-factor, andSaccharomyces cerevisiae alcoholdehydrogenase/glyceraldehyde-3-phosphate dehydrogenase (ADH2/GAP).

The control sequence may also be a polyadenylation sequence, a sequenceoperably linked to the 3′ terminus of the nucleotide sequence and, whentranscribed, is recognized by the host cell as a signal to addpolyadenosine residues to transcribed mRNA. Any polyadenylation sequencethat is functional in the host cell of choice may be used in the presentinvention.

Preferred polyadenylation sequences for filamentous fungal host cellsare obtained from the genes for Aspergillus oryzae TAKA amylase,Aspergillus niger glucoamylase, Aspergillus nidulans anthranilatesynthase, Fusarium oxysporum trypsin-like protease, and Aspergillusniger alpha-glucosidase.

Useful polyadenylation sequences for yeast host cells are described byGuo and Sherman, 1995, Molecular Cellular Biology 15: 5983-5990.

The control sequence may also be a signal peptide coding sequence thatencodes a signal peptide linked to the amino terminus of a polypeptideand directs the encoded polypeptide into the cell's secretory pathway.The 5′ end of the coding sequence of the nucleotide sequence mayinherently contain a signal peptide coding sequence naturally linked intranslation reading frame with the segment of the coding sequence thatencodes the secreted polypeptide. Alternatively, the 5′ end of thecoding sequence may contain a signal peptide coding sequence that isforeign to the coding sequence. The foreign signal peptide codingsequence may be required where the coding sequence does not naturallycontain a signal peptide coding sequence. Alternatively, the foreignsignal peptide coding sequence may simply replace the natural signalpeptide coding sequence in order to enhance secretion of thepolypeptide. However, any signal peptide coding sequence that directsthe expressed polypeptide into the secretory pathway of a host cell ofchoice, i.e., secreted into a culture medium, may be used in the presentinvention.

Effective signal peptide coding sequences for bacterial host cells arethe signal peptide coding sequences obtained from the genes for BacillusNCIB 11837 maltogenic amylase, Bacillus stearothermophilusalpha-amylase, Bacillus licheniformis subtilisin, Bacillus licheniformisbeta-lactamase, Bacillus stearothermophilus neutral proteases (nprT,nprS, nprM), and Bacillus subtilis prsA. Further signal peptides aredescribed by Simonen and Palva, 1993, Microbiological Reviews 57:109-137.

Effective signal peptide coding sequences for filamentous fungal hostcells are the signal peptide coding sequences obtained from the genesfor Aspergillus oryzae TAKA amylase, Aspergillus niger neutral amylase,Aspergillus niger glucoamylase, Rhizomucor miehei aspartic proteinase,Humicola insolens cellulase, Humicola insolens endoglucanase V, andHumicola lanuginosa lipase.

Useful signal peptides for yeast host cells are obtained from the genesfor Saccharomyces cerevisiae alpha-factor and Saccharomyces cerevisiaeinvertase. Other useful signal peptide coding sequences are described byRomanos et al., 1992, supra.

In a preferred aspect, the signal peptide comprises or consists of aminoacids 1 to 21 of SEQ ID NO: 2. In another preferred aspect, the signalpeptide coding sequence comprises or consists of nucleotides 1 to 63 ofSEQ ID NO: 1.

The control sequence may also be a propeptide coding sequence thatencodes a propeptide positioned at the amino terminus of a polypeptide.The resultant polypeptide is known as a proenzyme or propolypeptide (ora zymogen in some cases). A propeptide is generally inactive and can beconverted to a mature active polypeptide by catalytic or autocatalyticcleavage of the propeptide from the propolypeptide. The propeptidecoding sequence may be obtained from the genes for Bacillus subtilisalkaline protease (aprE), Bacillus subtilis neutral protease (nprT),Saccharomyces cerevisiae alpha-factor, Rhizomucor miehei asparticproteinase, and Myceliophthora thermophila laccase (WO 95/33836).

Where both signal peptide and propeptide sequences are present at theamino terminus of a polypeptide, the propeptide sequence is positionednext to the amino terminus of a polypeptide and the signal peptidesequence is positioned next to the amino terminus of the propeptidesequence.

It may also be desirable to add regulatory sequences that allow theregulation of the expression of the polypeptide relative to the growthof the host cell. Examples of regulatory systems are those that causethe expression of the gene to be turned on or off in response to achemical or physical stimulus, including the presence of a regulatorycompound. Regulatory systems in prokaryotic systems include the lac,tac, and trp operator systems. In yeast, the ADH2 system or GAL1 systemmay be used. In filamentous fungi, the TAKA alpha-amylase promoter,Aspergillus niger glucoamylase promoter, and Aspergillus oryzaeglucoamylase promoter may be used as regulatory sequences. Otherexamples of regulatory sequences are those that allow for geneamplification. In eukaryotic systems, these regulatory sequences includethe dihydrofolate reductase gene that is amplified in the presence ofmethotrexate, and the metallothionein genes that are amplified withheavy metals. In these cases, the nucleotide sequence encoding thepolypeptide would be operably linked with the regulatory sequence.

Expression Vectors

The present invention also relates to recombinant expression vectorscomprising a polynucleotide of the present invention, a promoter, andtranscriptional and translational stop signals. The various nucleicacids and control sequences described herein may be joined together toproduce a recombinant expression vector that may include one or more(several) convenient restriction sites to allow for insertion orsubstitution of the nucleotide sequence encoding the polypeptide at suchsites. Alternatively, a polynucleotide sequence of the present inventionmay be expressed by inserting the nucleotide sequence or a nucleic acidconstruct comprising the sequence into an appropriate vector forexpression. In creating the expression vector, the coding sequence islocated in the vector so that the coding sequence is operably linkedwith the appropriate control sequences for expression.

The recombinant expression vector may be any vector (e.g., a plasmid orvirus) that can be conveniently subjected to recombinant DNA proceduresand can bring about expression of the nucleotide sequence. The choice ofthe vector will typically depend on the compatibility of the vector withthe host cell into which the vector is to be introduced. The vectors maybe linear or closed circular plasmids.

The vector may be an autonomously replicating vector, i.e., a vectorthat exists as an extrachromosomal entity, the replication of which isindependent of chromosomal replication, e.g., a plasmid, anextrachromosomal element, a minichromosome, or an artificial chromosome.The vector may contain any means for assuring self-replication.Alternatively, the vector may be one that, when introduced into the hostcell, is integrated into the genome and replicated together with thechromosome(s) into which it has been integrated. Furthermore, a singlevector or plasmid or two or more vectors or plasmids that togethercontain the total DNA to be introduced into the genome of the host cell,or a transposon, may be used.

The vectors of the present invention preferably contain one or more(several) selectable markers that permit easy selection of transformed,transfected, transduced, or the like cells. A selectable marker is agene the product of which provides for biocide or viral resistance,resistance to heavy metals, prototrophy to auxotrophs, and the like.

Examples of bacterial selectable markers are the dal genes from Bacillussubtilis or Bacillus licheniformis, or markers that confer antibioticresistance such as ampicillin, kanamycin, chloramphenicol, ortetracycline resistance. Suitable markers for yeast host cells are ADE2,HIS3, LEU2, LYS2, MET3, TRP1, and URA3. Selectable markers for use in afilamentous fungal host cell include, but are not limited to, amdS(acetamidase), argB (ornithine carbamoyltransferase), bar(phosphinothricin acetyltransferase), hph (hygromycinphosphotransferase), niaD (nitrate reductase), pyrG(orotidine-5′-phosphate decarboxylase), sC (sulfate adenyltransferase),and trpC (anthranilate synthase), as well as equivalents thereof.Preferred for use in an Aspergillus cell are the amdS and pyrG genes ofAspergillus nidulans or Aspergillus oryzae and the bar gene ofStreptomyces hygroscopicus.

The vectors of the present invention preferably contain an element(s)that permits integration of the vector into the host cell's genome orautonomous replication of the vector in the cell independent of thegenome.

For integration into the host cell genome, the vector may rely on thepolynucleotide's sequence encoding the polypeptide or any other elementof the vector for integration into the genome by homologous ornonhomologous recombination. Alternatively, the vector may containadditional nucleotide sequences for directing integration by homologousrecombination into the genome of the host cell at a precise location(s)in the chromosome(s). To increase the likelihood of integration at aprecise location, the integrational elements should preferably contain asufficient number of nucleic acids, such as 100 to 10,000 base pairs,preferably 400 to 10,000 base pairs, and most preferably 800 to 10,000base pairs, which have a high degree of identity to the correspondingtarget sequence to enhance the probability of homologous recombination.The integrational elements may be any sequence that is homologous withthe target sequence in the genome of the host cell. Furthermore, theintegrational elements may be non-encoding or encoding nucleotidesequences. On the other hand, the vector may be integrated into thegenome of the host cell by non-homologous recombination.

For autonomous replication, the vector may further comprise an origin ofreplication enabling the vector to replicate autonomously in the hostcell in question. The origin of replication may be any plasmidreplicator mediating autonomous replication that functions in a cell.The term “origin of replication” or “plasmid replicator” is definedherein as a nucleotide sequence that enables a plasmid or vector toreplicate in vivo.

Examples of bacterial origins of replication are the origins ofreplication of plasmids pBR322, pUC19, pACYC177, and pACYC184 permittingreplication in E. coli, and pUB110, pE194, pTA1060, and pAMR1 permittingreplication in Bacillus.

Examples of origins of replication for use in a yeast host cell are the2 micron origin of replication, ARS1, ARS4, the combination of ARS1 andCEN3, and the combination of ARS4 and CEN6.

Examples of origins of replication useful in a filamentous fungal cellare AMA1 and ANS1 (Gems et al., 1991, Gene 98: 61-67; Cullen et al.,1987, Nucleic Acids Research 15: 9163-9175; WO 00/24883). Isolation ofthe AMA1 gene and construction of plasmids or vectors comprising thegene can be accomplished according to the methods disclosed in WO00/24883.

More than one copy of a polynucleotide of the present invention may beinserted into a host cell to increase production of the gene product. Anincrease in the copy number of the polynucleotide can be obtained byintegrating at least one additional copy of the sequence into the hostcell genome or by including an amplifiable selectable marker gene withthe polynucleotide where cells containing amplified copies of theselectable marker gene, and thereby additional copies of thepolynucleotide, can be selected for by cultivating the cells in thepresence of the appropriate selectable agent.

The procedures used to ligate the elements described above to constructthe recombinant expression vectors of the present invention are wellknown to one skilled in the art (see, e.g., Sambrook et al., 1989,supra).

Host Cells

The present invention also relates to recombinant host cells, comprisingan isolated polynucleotide of the present invention, which areadvantageously used in the recombinant production of the polypeptideshaving cellulolytic enhancing activity. A vector comprising apolynucleotide of the present invention is introduced into a host cellso that the vector is maintained as a chromosomal integrant or as aself-replicating extra-chromosomal vector as described earlier. The term“host cell” encompasses any progeny of a parent cell that is notidentical to the parent cell due to mutations that occur duringreplication. The choice of a host cell will to a large extent dependupon the gene encoding the polypeptide and its source.

The host cell may be any cell useful in the recombinant production of apolypeptide of the present invention, e.g., a prokaryote or a eukaryote.

The prokaryotic host cell may be any Gram positive bacterium or a Gramnegative bacterium. Gram positive bacteria include, but not limited to,Bacillus, Streptococcus, Streptomyces, Staphylococcus, Enterococcus,Lactobacillus, Lactococcus, Clostridium, Geobacillus, andOceanobacillus. Gram negative bacteria include, but not limited to, E.coli, Pseudomonas, Salmonella, Campylobacter, Helicobacter,Flavobacterium, Fusobacterium, Ilyobacter, Neisseria, and Ureaplasma.

The bacterial host cell may be any Bacillus cell. Bacillus cells usefulin the practice of the present invention include, but are not limitedto, Bacillus alkalophilus, Bacillus amyloliquefaciens, Bacillus brevis,Bacillus circulans, Bacillus clausii, Bacillus coagulans, Bacillusfirmus, Bacillus lautus, Bacillus lentus, Bacillus licheniformis,Bacillus megaterium, Bacillus pumilus, Bacillus stearothermophilus,Bacillus subtilis, and Bacillus thuringiensis cells.

In a preferred aspect, the bacterial host cell is a Bacillusamyloliquefaciens cell. In another preferred aspect, the bacterial hostcell is a Bacillus clausii cell. In another preferred aspect, thebacterial host cell is a Bacillus lentus cell. In another preferredaspect, the bacterial host cell is a Bacillus licheniformis cell. Inanother preferred aspect, the bacterial host cell is a Bacillusstearothermophilus cell. In another preferred aspect, the bacterial hostcell is a Bacillus subtilis cell.

The bacterial host cell may also be any Streptococcus cell.Streptococcus cells useful in the practice of the present inventioninclude, but are not limited to, Streptococcus equisimilis,Streptococcus pyogenes, Streptococcus uberis, and Streptococcus equisubsp. Zooepidemicus cells.

In a preferred aspect, the bacterial host cell is a Streptococcusequisimilis cell. In another preferred aspect, the bacterial host cellis a Streptococcus pyogenes cell. In another preferred aspect, thebacterial host cell is a Streptococcus uberis cell. In another preferredaspect, the bacterial host cell is a Streptococcus equi subsp.Zooepidemicus cell.

The bacterial host cell may also be any Streptomyces cell. Streptomycescells useful in the practice of the present invention include, but arenot limited to, Streptomyces achromogenes, Streptomyces avermitilis,Streptomyces coelicolor, Streptomyces griseus, and Streptomyces lividanscells.

In a preferred aspect, the bacterial host cell is a Streptomycesachromogenes cell. In another preferred aspect, the bacterial host cellis a Streptomyces avermitilis cell. In another preferred aspect, thebacterial host cell is a Streptomyces coelicolor cell. In anotherpreferred aspect, the bacterial host cell is a Streptomyces griseuscell. In another preferred aspect, the bacterial host cell is aStreptomyces lividans cell.

The introduction of DNA into a Bacillus cell may, for instance, beeffected by protoplast transformation (see, e.g., Chang and Cohen, 1979,Molecular General Genetics 168: 111-115), by using competent cells (see,e.g., Young and Spizizen, 1961, Journal of Bacteriology 81: 823-829, orDubnau and Davidoff-Abelson, 1971, Journal of Molecular Biology 56:209-221), by electroporation (see, e.g., Shigekawa and Dower, 1988,Biotechniques 6: 742-751), or by conjugation (see, e.g., Koehler andThorne, 1987, Journal of Bacteriology 169: 5271-5278). The introductionof DNA into an E coli cell may, for instance, be effected by protoplasttransformation (see, e.g., Hanahan, 1983, J. Mol. Biol. 166: 557-580) orelectroporation (see, e.g., Dower et al., 1988, Nucleic Acids Res. 16:6127-6145). The introduction of DNA into a Streptomyces cell may, forinstance, be effected by protoplast transformation and electroporation(see, e.g., Gong et al., 2004, Folia Microbiol. (Praha) 49: 399-405), byconjugation (see, e.g., Mazodier et al., 1989, J. Bacteriol. 171:3583-3585), or by transduction (see, e.g., Burke et al., 2001, Proc.Natl. Acad. Sci. USA 98: 6289-6294). The introduction of DNA into aPseudomonas cell may, for instance, be effected by electroporation (see,e.g., Choi et al., 2006, J. Microbiol. Methods 64: 391-397) or byconjugation (see, e.g., Pinedo and Smets, 2005, Appl. Environ.Microbiol. 71: 51-57). The introduction of DNA into a Streptococcus cellmay, for instance, be effected by natural competence (see, e.g., Perryand Kuramitsu, 1981, Infect. Immun. 32: 1295-1297), by protoplasttransformation (see, e.g., Catt and Jollick, 1991, Microbios. 68:189-207, by electroporation (see, e.g., Buckley et al., 1999, Appl.Environ. Microbiol. 65: 3800-3804) or by conjugation (see, e.g.,Clewell, 1981, Microbiol. Rev. 45: 409-436). However, any method knownin the art for introducing DNA into a host cell can be used.

The host cell may also be a eukaryote, such as a mammalian, insect,plant, or fungal cell.

In a preferred aspect, the host cell is a fungal cell. “Fungi” as usedherein includes the phyla Ascomycota, Basidiomycota, Chytridiomycota,and Zygomycota (as defined by Hawksworth et al., In, Ainsworth andBisby's Dictionary of The Fungi, 8th edition, 1995, CAB International,University Press, Cambridge, UK) as well as the Oomycota (as cited inHawksworth et al., 1995, supra, page 171) and all mitosporic fungi(Hawksworth et al., 1995, supra).

In a more preferred aspect, the fungal host cell is a yeast cell.“Yeast” as used herein includes ascosporogenous yeast (Endomycetales),basidiosporogenous yeast, and yeast belonging to the Fungi Imperfecti(Blastomycetes). Since the classification of yeast may change in thefuture, for the purposes of this invention, yeast shall be defined asdescribed in Biology and Activities of Yeast (Skinner, F. A., Passmore,S. M., and Davenport, R. R., eds, Soc. App. Bacteriol. Symposium SeriesNo. 9, 1980).

In an even more preferred aspect, the yeast host cell is a Candida,Hansenula, Kluyveromyces, Pichia, Saccharomyces, Schizosaccharomyces, orYarrowia cell.

In a most preferred aspect, the yeast host cell is a Saccharomycescarlsbergensis, Saccharomyces cerevisiae, Saccharomyces diastaticus,Saccharomyces douglasii, Saccharomyces kluyveri, Saccharomycesnorbensis, or Saccharomyces oviformis cell. In another most preferredaspect, the yeast host cell is a Kluyveromyces lactis cell. In anothermost preferred aspect, the yeast host cell is a Yarrowia lipolyticacell.

In another more preferred aspect, the fungal host cell is a filamentousfungal cell. “Filamentous fungi” include all filamentous forms of thesubdivision Eumycota and Oomycota (as defined by Hawksworth et al.,1995, supra). The filamentous fungi are generally characterized by amycelial wall composed of chitin, cellulose, glucan, chitosan, mannan,and other complex polysaccharides. Vegetative growth is by hyphalelongation and carbon catabolism is obligately aerobic. In contrast,vegetative growth by yeasts such as Saccharomyces cerevisiae is bybudding of a unicellular thallus and carbon catabolism may befermentative.

In an even more preferred aspect, the filamentous fungal host cell is anAcremonium, Aspergillus, Aureobasidium, Bjerkandera, Ceriporiopsis,Chrysosporium, Coprinus, Coriolus, Cryptococcus, Filibasidium, Fusarium,Humicola, Magnaporthe, Mucor, Myceliophthora, Neocallimastix,Neurospora, Paecilomyces, Penicillium, Phanerochaete, Phlebia,Piromyces, Pleurotus, Schizophyllum, Talaromyces, Thermoascus,Thielavia, Tolypocladium, Trametes, or Trichoderma cell.

In a most preferred aspect, the filamentous fungal host cell is anAspergillus awamori, Aspergillus fumigatus, Aspergillus foetidus,Aspergillus japonicus, Aspergillus nidulans, Aspergillus niger orAspergillus oryzae cell. In another most preferred aspect, thefilamentous fungal host cell is a Fusarium bactridioides, Fusariumcerealis, Fusarium crookwellense, Fusarium culmorum, Fusariumgraminearum, Fusarium graminum, Fusarium heterosporum, Fusarium negundi,Fusarium oxysporum, Fusarium reticulatum, Fusarium roseum, Fusariumsambucinum, Fusarium sarcochroum, Fusarium sporotrichioides, Fusariumsulphureum, Fusarium torulosum, Fusarium trichothecioides, or Fusariumvenenatum cell. In another most preferred aspect, the filamentous fungalhost cell is a Bjerkandera adusta, Ceriporiopsis aneirina, Ceriporiopsisaneirina, Ceriporiopsis caregiea, Ceriporiopsis gilvescens,Ceriporiopsis pannocinta, Ceriporiopsis rivulosa, Ceriporiopsis subrufa,Ceriporiopsis subvermispora, Chrysosporium keratinophilum, Chrysosporiumlucknowense, Chrysosporium tropicum, Chrysosporium merdarium,Chrysosporium inops, Chrysosporium pannicola, Chrysosporiumqueenslandicum, Chrysosporium zonatum, Coprinus cinereus, Coriolushirsutus, Humicola insolens, Humicola lanuginosa, Mucor miehei,Myceliophthora thermophila, Neurospora crassa, Penicillium purpurogenum,Phanerochaete chrysosporium, Phlebia radiata, Pleurotus eryngii,Thielavia terrestris, Trametes villosa, Trametes versicolor, Trichodermaharzianum, Trichoderma koningii, Trichoderma longibrachiatum,Trichoderma reesei, or Trichoderma viride cell.

In another most preferred aspect, the filamentous fungal host cell is anAspergillus niger cell. In another most preferred aspect, thefilamentous fungal host cell is an Aspergillus oryzae cell. In anothermost preferred aspect, the filamentous fungal host cell is aChrysosporium lucknowense cell. In another most preferred aspect, thefilamentous fungal host cell is a Fusarium venenatum cell. In anothermost preferred aspect, the filamentous fungal host cell is aMyceliophthora thermophila cell. In another most preferred aspect, thefilamentous fungal host cell is a Trichoderma reesei cell.

Fungal cells may be transformed by a process involving protoplastformation, transformation of the protoplasts, and regeneration of thecell wall in a manner known per se. Suitable procedures fortransformation of Aspergillus and Trichoderma host cells are describedin EP 238 023 and Yelton et al., 1984, Proceedings of the NationalAcademy of Sciences USA 81: 1470-1474. Suitable methods for transformingFusarium species are described by Malardier et al., 1989, Gene 78:147-156, and WO 96/00787. Yeast may be transformed using the proceduresdescribed by Becker and Guarente, In Abelson, J. N. and Simon, M. I.,editors, Guide to Yeast Genetics and Molecular Biology, Methods inEnzymology, Volume 194, pp 182-187, Academic Press, Inc., New York; Itoet al., 1983, Journal of Bacteriology 153: 163; and Hinnen et al., 1978,Proceedings of the National Academy of Sciences USA 75: 1920.

Methods of Production

The present invention also relates to methods of producing a polypeptideof the present invention, comprising: (a) cultivating a cell, which inits wild-type form produces the polypeptide, under conditions conducivefor production of the polypeptide; and (b) recovering the polypeptide.In a preferred aspect, the cell is of the genus Thermoascus. In a morepreferred aspect, the cell is Thermoascus aurantiacus. In a mostpreferred aspect, the cell is Thermoascus aurantiacus CGMCC 0670.

The present invention also relates to methods of producing a polypeptideof the present invention, comprising: (a) cultivating a recombinant hostcell, as described herein, under conditions conducive for production ofthe polypeptide; and (b) recovering the polypeptide.

The present invention also relates to methods of producing a polypeptideof the present invention, comprising: (a) cultivating a recombinant hostcell under conditions conducive for production of the polypeptide,wherein the host cell comprises a mutant nucleotide sequence having atleast one mutation in the mature polypeptide coding sequence of SEQ IDNO: 1, wherein the mutant nucleotide sequence encodes a polypeptide thatcomprises or consists of the mature polypeptide of SEQ ID NO: 2; and (b)recovering the polypeptide.

In the production methods of the present invention, the cells arecultivated in a nutrient medium suitable for production of thepolypeptide using methods well known in the art. For example, the cellmay be cultivated by shake flask cultivation, and small-scale orlarge-scale fermentation (including continuous, batch, fed-batch, orsolid state fermentations) in laboratory or industrial fermentorsperformed in a suitable medium and under conditions allowing thepolypeptide to be expressed and/or isolated. The cultivation takes placein a suitable nutrient medium comprising carbon and nitrogen sources andinorganic salts, using procedures known in the art. Suitable media areavailable from commercial suppliers or may be prepared according topublished compositions (e.g., in catalogues of the American Type CultureCollection). If the polypeptide is secreted into the nutrient medium,the polypeptide can be recovered directly from the medium. If thepolypeptide is not secreted into the medium, it can be recovered fromcell lysates.

The polypeptides may be detected using methods known in the art that arespecific for the polypeptides. These detection methods may include useof specific antibodies, formation of an enzyme product, or disappearanceof an enzyme substrate. For example, an enzyme assay may be used todetermine the activity of the polypeptide as described herein.

The resulting polypeptide may be recovered using methods known in theart. For example, the polypeptide may be recovered from the nutrientmedium by conventional procedures including, but not limited to,centrifugation, filtration, extraction, spray-drying, evaporation, orprecipitation.

The polypeptides of the present invention may be purified by a varietyof procedures known in the art including, but not limited to,chromatography (e.g., ion exchange, affinity, hydrophobic,chromatofocusing, and size exclusion), electrophoretic procedures (e.g.,preparative isoelectric focusing), differential solubility (e.g.,ammonium sulfate precipitation), SDS-PAGE, or extraction (see, e.g.,Protein Purification, J.-C. Janson and Lars Ryden, editors, VCHPublishers, New York, 1989) to obtain substantially pure polypeptides.

Plants

The present invention also relates to plants, e.g., a transgenic plant,plant part, or plant cell, comprising an isolated polynucleotideencoding a polypeptide having cellulolytic enhancing activity of thepresent invention so as to express and produce the polypeptide inrecoverable quantities. The polypeptide may be recovered from the plantor plant part. Alternatively, the plant or plant part containing therecombinant polypeptide may be used as such for improving the quality ofa food or feed, e.g., improving nutritional value, palatability, andrheological properties, or to destroy an antinutritive factor.

The transgenic plant can be dicotyledonous (a dicot) or monocotyledonous(a monocot). Examples of monocot plants are grasses, such as meadowgrass (blue grass, Poa), forage grass such as Festuca, Lolium, temperategrass, such as Agrostis, and cereals, e.g., wheat, oats, rye, barley,rice, sorghum, and maize (corn).

Examples of dicot plants are tobacco, legumes, such as lupins, potato,sugar beet, pea, bean and soybean, and cruciferous plants (familyBrassicaceae), such as cauliflower, rape seed, and the closely relatedmodel organism Arabidopsis thaliana.

Examples of plant parts are stem, callus, leaves, root, fruits, seeds,and tubers as well as the individual tissues comprising these parts,e.g., epidermis, mesophyll, parenchyme, vascular tissues, meristems.Specific plant cell compartments, such as chloroplasts, apoplasts,mitochondria, vacuoles, peroxisomes and cytoplasm are also considered tobe a plant part. Furthermore, any plant cell, whatever the tissueorigin, is considered to be a plant part.

Likewise, plant parts such as specific tissues and cells isolated tofacilitate the utilisation of the invention are also considered plantparts, e.g., embryos, endosperms, aleurone and seeds coats.

Also included within the scope of the present invention are the progenyof such plants, plant parts, and plant cells.

The transgenic plant or plant cell expressing a polypeptide of thepresent invention may be constructed in accordance with methods known inthe art. In short, the plant or plant cell is constructed byincorporating one or more (several) expression constructs encoding apolypeptide of the present invention into the plant host genome orchloroplast genome and propagating the resulting modified plant or plantcell into a transgenic plant or plant cell.

The expression construct is conveniently a nucleic acid construct thatcomprises a polynucleotide encoding a polypeptide of the presentinvention operably linked with appropriate regulatory sequences requiredfor expression of the nucleotide sequence in the plant or plant part ofchoice. Furthermore, the expression construct may comprise a selectablemarker useful for identifying host cells into which the expressionconstruct has been integrated and DNA sequences necessary forintroduction of the construct into the plant in question (the latterdepends on the DNA introduction method to be used).

The choice of regulatory sequences, such as promoter and terminatorsequences and optionally signal or transit sequences, is determined, forexample, on the basis of when, where, and how the polypeptide is desiredto be expressed. For instance, the expression of the gene encoding apolypeptide of the present invention may be constitutive or inducible,or may be developmental, stage or tissue specific, and the gene productmay be targeted to a specific tissue or plant part such as seeds orleaves. Regulatory sequences are, for example, described by Tague etal., 1988, Plant Physiology 86: 506.

For constitutive expression, the 35S-CaMV, the maize ubiquitin 1, andthe rice actin 1 promoter may be used (Franck et al., 1980, Cell 21:285-294; Christensen et al., 1992, Plant Mol. Biol. 18: 675-689; Zhanget al., 1991, Plant Cell 3: 1155-1165). Organ-specific promoters may be,for example, a promoter from storage sink tissues such as seeds, potatotubers, and fruits (Edwards and Coruzzi, 1990, Ann. Rev. Genet. 24:275-303), or from metabolic sink tissues such as meristems (Ito et al.,1994, Plant Mol. Biol. 24: 863-878), a seed specific promoter such asthe glutelin, prolamin, globulin, or albumin promoter from rice (Wu etal., 1998, Plant and Cell Physiology 39: 885-889), a Vicia faba promoterfrom the legumin B4 and the unknown seed protein gene from Vicia faba(Conrad et al., 1998, Journal of Plant Physiology 152: 708-711), apromoter from a seed oil body protein (Chen et al., 1998, Plant and CellPhysiology 39: 935-941), the storage protein napA promoter from Brassicanapus, or any other seed specific promoter known in the art, e.g., asdescribed in WO 91/14772. Furthermore, the promoter may be a leafspecific promoter such as the rbcs promoter from rice or tomato (Kyozukaet al., 1993, Plant Physiology 102: 991-1000, the chlorella virusadenine methyltransferase gene promoter (Mitra and Higgins, 1994, PlantMolecular Biology 26: 85-93), or the aldP gene promoter from rice(Kagaya et al., 1995, Molecular and General Genetics 248: 668-674), or awound inducible promoter such as the potato pin2 promoter (Xu et al.,1993, Plant Molecular Biology 22: 573-588). Likewise, the promoter mayinducible by abiotic treatments such as temperature, drought, oralterations in salinity or induced by exogenously applied substancesthat activate the promoter, e.g., ethanol, oestrogens, plant hormonessuch as ethylene, abscisic acid, and gibberellic acid, and heavy metals.

A promoter enhancer element may also be used to achieve higherexpression of a polypeptide of the present invention in the plant. Forinstance, the promoter enhancer element may be an intron that is placedbetween the promoter and the nucleotide sequence encoding a polypeptideof the present invention. For instance, Xu et al., 1993, supra, disclosethe use of the first intron of the rice actin 1 gene to enhanceexpression.

The selectable marker gene and any other parts of the expressionconstruct may be chosen from those available in the art.

The nucleic acid construct is incorporated into the plant genomeaccording to conventional techniques known in the art, includingAgrobacterium-mediated transformation, virus-mediated transformation,microinjection, particle bombardment, biolistic transformation, andelectroporation (Gasser et al., 1990, Science 244: 1293; Potrykus, 1990,Bio/Technology 8: 535; Shimamoto et al., 1989, Nature 338: 274).

Presently, Agrobacterium tumefaciens-mediated gene transfer is themethod of choice for generating transgenic dicots (for a review, seeHooykas and Schilperoort, 1992, Plant Molecular Biology 19: 15-38) andcan also be used for transforming monocots, although othertransformation methods are often used for these plants. Presently, themethod of choice for generating transgenic monocots is particlebombardment (microscopic gold or tungsten particles coated with thetransforming DNA) of embryonic calli or developing embryos (Christou,1992, Plant Journal 2: 275-281; Shimamoto, 1994, Current OpinionBiotechnology 5: 158-162; Vasil et al., 1992, Bio/Technology 10:667-674). An alternative method for transformation of monocots is basedon protoplast transformation as described by Omirulleh et al., 1993,Plant Molecular Biology 21: 415-428.

Following transformation, the transformants having incorporated theexpression construct are selected and regenerated into whole plantsaccording to methods well-known in the art. Often the transformationprocedure is designed for the selective elimination of selection geneseither during regeneration or in the following generations by using, forexample, co-transformation with two separate T-DNA constructs or sitespecific excision of the selection gene by a specific recombinase.

The present invention also relates to methods of producing a polypeptideof the present invention comprising: (a) cultivating a transgenic plantor a plant cell comprising a polynucleotide encoding the polypeptidehaving cellulolytic enhancing activity of the present invention underconditions conducive for production of the polypeptide; and (b)recovering the polypeptide.

In embodiments, in addition to direct transformation of a particularplant genotype with a construct prepared according to the presentinvention, transgenic plants may be made by crossing a plant having aconstruct of the present invention to a second plant lacking theconstruct. For example, a construct encoding a polypeptide havingcellulolytic enhancing activity or a portion thereof can be introducedinto a particular plant variety by crossing, without the need for everdirectly transforming a plant of that given variety. Therefore, thepresent invention not only encompasses a plant directly regenerated fromcells which have been transformed in accordance with the presentinvention, but also the progeny of such plants. As used herein, progenymay refer to the offspring of any generation of a parent plant preparedin accordance with the present invention. Such progeny may include a DNAconstruct prepared in accordance with the present invention, or aportion of a DNA construct prepared in accordance with the presentinvention. In embodiments, crossing results in a transgene of thepresent invention being introduced into a plant line by crosspollinating a starting line with a donor plant line that includes atransgene of the present invention. Non-limiting examples of such stepsare further articulated in U.S. Pat. No. 7,151,204.

It is envisioned that plants including a polypeptide having cellulolyticenhancing activity of the present invention include plants generatedthrough a process of backcross conversion. For examples, plants of thepresent invention include plants referred to as a backcross convertedgenotype, line, inbred, or hybrid.

In embodiments, genetic markers may be used to assist in theintrogression of one or more transgenes of the invention from onegenetic background into another. Marker assisted selection offersadvantages relative to conventional breeding in that it can be used toavoid errors caused by phenotypic variations. Further, genetic markersmay provide data regarding the relative degree of elite germplasm in theindividual progeny of a particular cross. For example, when a plant witha desired trait which otherwise has a non-agronomically desirablegenetic background is crossed to an elite parent, genetic markers may beused to select progeny which not only possess the trait of interest, butalso have a relatively large proportion of the desired germplasm. Inthis way, the number of generations required to introgress one or moretraits into a particular genetic background is minimized.

Removal or Reduction of Cellulolytic Enhancing Activity

The present invention also relates to methods of producing a mutant of aparent cell, which comprises disrupting or deleting a polynucleotide, ora portion thereof, encoding a polypeptide of the present invention,which results in the mutant cell producing less of the polypeptide thanthe parent cell when cultivated under the same conditions.

The mutant cell may be constructed by reducing or eliminating expressionof a nucleotide sequence encoding a polypeptide of the present inventionusing methods well known in the art, for example, insertions,disruptions, replacements, or deletions. In a preferred aspect, thenucleotide sequence is inactivated. The nucleotide sequence to bemodified or inactivated may be, for example, the coding region or a partthereof essential for activity, or a regulatory element required for theexpression of the coding region. An example of such a regulatory orcontrol sequence may be a promoter sequence or a functional partthereof, i.e., a part that is sufficient for affecting expression of thenucleotide sequence. Other control sequences for possible modificationinclude, but are not limited to, a leader, polyadenylation sequence,propeptide sequence, signal peptide sequence, transcription terminator,and transcriptional activator.

Modification or inactivation of the nucleotide sequence may be performedby subjecting the parent cell to mutagenesis and selecting for mutantcells in which expression of the nucleotide sequence has been reduced oreliminated. The mutagenesis, which may be specific or random, may beperformed, for example, by use of a suitable physical or chemicalmutagenizing agent, by use of a suitable oligonucleotide, or bysubjecting the DNA sequence to PCR generated mutagenesis. Furthermore,the mutagenesis may be performed by use of any combination of thesemutagenizing agents.

Examples of a physical or chemical mutagenizing agent suitable for thepresent purpose include ultraviolet (UV) irradiation, hydroxylamine,N-methyl-N′-nitro-N-nitrosoguanidine (MNNG), O-methyl hydroxylamine,nitrous acid, ethyl methane sulphonate (EMS), sodium bisulphite, formicacid, and nucleotide analogues.

When such agents are used, the mutagenesis is typically performed byincubating the parent cell to be mutagenized in the presence of themutagenizing agent of choice under suitable conditions, and screeningand/or selecting for mutant cells exhibiting reduced or no expression ofthe gene.

Modification or inactivation of the nucleotide sequence may beaccomplished by introduction, substitution, or removal of one or more(several) nucleotides in the gene or a regulatory element required forthe transcription or translation thereof. For example, nucleotides maybe inserted or removed so as to result in the introduction of a stopcodon, the removal of the start codon, or a change in the open readingframe. Such modification or inactivation may be accomplished bysite-directed mutagenesis or PCR generated mutagenesis in accordancewith methods known in the art. Although, in principle, the modificationmay be performed in vivo, i.e., directly on the cell expressing thenucleotide sequence to be modified, it is preferred that themodification be performed in vitro as exemplified below.

An example of a convenient way to eliminate or reduce expression of anucleotide sequence by a cell is based on techniques of genereplacement, gene deletion, or gene disruption. For example, in the genedisruption method, a nucleic acid sequence corresponding to theendogenous nucleotide sequence is mutagenized in vitro to produce adefective nucleic acid sequence that is then transformed into the parentcell to produce a defective gene. By homologous recombination, thedefective nucleic acid sequence replaces the endogenous nucleotidesequence. It may be desirable that the defective nucleotide sequencealso encodes a marker that may be used for selection of transformants inwhich the nucleotide sequence has been modified or destroyed. In aparticularly preferred aspect, the nucleotide sequence is disrupted witha selectable marker such as those described herein.

Alternatively, modification or inactivation of the nucleotide sequencemay be performed by established anti-sense or RNAi techniques using asequence complementary to the nucleotide sequence. More specifically,expression of the nucleotide sequence by a cell may be reduced oreliminated by introducing a sequence complementary to the nucleotidesequence of the gene that may be transcribed in the cell and is capableof hybridizing to the mRNA produced in the cell. Under conditionsallowing the complementary anti-sense nucleotide sequence to hybridizeto the mRNA, the amount of protein translated is thus reduced oreliminated.

The present invention further relates to a mutant cell of a parent cellthat comprises a disruption or deletion of a nucleotide sequenceencoding the polypeptide or a control sequence thereof, which results inthe mutant cell producing less of the polypeptide or no polypeptidecompared to the parent cell.

The polypeptide-deficient mutant cells so created are particularlyuseful as host cells for the expression of native and/or heterologouspolypeptides. Therefore, the present invention further relates tomethods of producing a native or heterologous polypeptide, comprising:(a) cultivating the mutant cell under conditions conducive forproduction of the polypeptide; and (b) recovering the polypeptide. Theterm “heterologous polypeptides” is defined herein as polypeptides thatare not native to the host cell, a native protein in which modificationshave been made to alter the native sequence, or a native protein whoseexpression is quantitatively altered as a result of a manipulation ofthe host cell by recombinant DNA techniques.

In a further aspect, the present invention relates to a method ofproducing a protein product essentially free of cellulolytic enhancingactivity by fermentation of a cell that produces both a polypeptide ofthe present invention as well as the protein product of interest byadding an effective amount of an agent capable of inhibitingcellulolytic enhancing activity to the fermentation broth before,during, or after the fermentation has been completed, recovering theproduct of interest from the fermentation broth, and optionallysubjecting the recovered product to further purification.

In a further aspect, the present invention relates to a method ofproducing a protein product essentially free of cellulolytic enhancingactivity by cultivating the cell under conditions permitting theexpression of the product, subjecting the resultant culture broth to acombined pH and temperature treatment so as to reduce the cellulolyticenhancing activity substantially, and recovering the product from theculture broth. Alternatively, the combined pH and temperature treatmentmay be performed on an enzyme preparation recovered from the culturebroth. The combined pH and temperature treatment may optionally be usedin combination with a treatment with a cellulolytic enhancing inhibitor.

In accordance with this aspect of the invention, it is possible toremove at least 60%, preferably at least 75%, more preferably at least85%, still more preferably at least 95%, and most preferably at least99% of the cellulolytic enhancing activity. Complete removal ofcellulolytic enhancing activity may be obtained by use of this method.

The combined pH and temperature treatment is preferably carried out at apH in the range of 2-4 or 9-11 and a temperature in the range of atleast 60-70° C. for a sufficient period of time to attain the desiredeffect, where typically, 30 to 60 minutes is sufficient.

The methods used for cultivation and purification of the product ofinterest may be performed by methods known in the art.

The methods of the present invention for producing an essentiallycellulolytic enhancing-free product is of particular interest in theproduction of eukaryotic polypeptides, in particular fungal proteinssuch as enzymes. The enzyme may be selected from, e.g., an amylolyticenzyme, lipolytic enzyme, proteolytic enzyme, cellulolytic enzyme,oxidoreductase, or plant cell-wall degrading enzyme. Examples of suchenzymes include an aminopeptidase, amylase, amyloglucosidase,carbohydrase, carboxypeptidase, catalase, cellobiohydrolase, cellulase,chitinase, cutinase, cyclodextrin glycosyltransferase,deoxyribonuclease, endoglucanase, esterase, galactosidase,beta-galactosidase, glucoamylase, glucose oxidase, glucosidase,haloperoxidase, hemicellulase, invertase, isomerase, laccase, ligase,lipase, lyase, mannosidase, oxidase, pectinolytic enzyme, peroxidase,phytase, phenoloxidase, polyphenoloxidase, proteolytic enzyme,ribonuclease, transferase, transglutaminase, or xylanase. Thecellulolytic enhancing-deficient cells may also be used to expressheterologous proteins of pharmaceutical interest such as hormones,growth factors, receptors, and the like.

It will be understood that the term “eukaryotic polypeptides” includesnot only native polypeptides, but also those polypeptides, e.g.,enzymes, which have been modified by amino acid substitutions, deletionsor additions, or other such modifications to enhance activity,thermostability, pH tolerance and the like.

In a further aspect, the present invention relates to a protein productessentially free from cellulolytic enhancing activity that is producedby a method of the present invention.

Methods of Inhibiting Expression of a Polypeptide Having CellulolyticEnhancing Activity

The present invention also relates to methods of inhibiting theexpression of a polypeptide having cellulolytic enhancing activity in acell, comprising administering to the cell or expressing in the cell adouble-stranded RNA (dsRNA) molecule, wherein the dsRNA comprises asubsequence of a polynucleotide of the present invention. In a preferredaspect, the dsRNA is about 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25 ormore duplex nucleotides in length.

The dsRNA is preferably a small interfering RNA (siRNA) or a micro RNA(miRNA). In a preferred aspect, the dsRNA is small interfering RNA(siRNAs) for inhibiting transcription. In another preferred aspect, thedsRNA is micro RNA (miRNAs) for inhibiting translation.

The present invention also relates to such double-stranded RNA (dsRNA)molecules, comprising a portion of the mature polypeptide codingsequence of SEQ ID NO: 1 for inhibiting expression of a polypeptidehaving cellulolytic enhancing activity in a cell. While the presentinvention is not limited by any particular mechanism of action, thedsRNA can enter a cell and cause the degradation of a single-strandedRNA (ssRNA) of similar or identical sequences, including endogenousmRNAs. When a cell is exposed to dsRNA, mRNA from the homologous gene isselectively degraded by a process called RNA interference (RNAi).

The dsRNAs of the present invention can be used in gene-silencing. Inone aspect, the invention provides methods to selectively degrade RNAusing the dsRNAis of the present invention. The process may be practicedin vitro, ex vivo or in vivo. In one aspect, the dsRNA molecules can beused to generate a loss-of-function mutation in a cell, an organ or ananimal. Methods for making and using dsRNA molecules to selectivelydegrade RNA are well known in the art, see, for example, U.S. Pat. No.6,506,559; U.S. Pat. No. 6,511,824; U.S. Pat. No. 6,515,109; and U.S.Pat. No. 6,489,127.

Compositions

The present invention also relates to compositions comprising apolypeptide of the present invention. Preferably, the compositions areenriched in such a polypeptide. The term “enriched” indicates that thecellulolytic enhancing activity of the composition has been increased,e.g., with an enrichment factor of at least 1.1.

The composition may comprise a polypeptide of the present invention asthe major enzymatic component, e.g., a mono-component composition.Alternatively, the composition may comprise multiple enzymaticactivities, such as an aminopeptidase, amylase, carbohydrase,carboxypeptidase, catalase, cellulase, chitinase, cutinase, cyclodextringlycosyltransferase, deoxyribonuclease, esterase, alpha-galactosidase,beta-galactosidase, glucoamylase, alpha-glucosidase, beta-glucosidase,haloperoxidase, invertase, laccase, lipase, mannosidase, oxidase,pectinolytic enzyme, peptidoglutaminase, peroxidase, phytase,polyphenoloxidase, proteolytic enzyme, ribonuclease, transglutaminase,or xylanase. The additional enzyme(s) may be produced, for example, by amicroorganism belonging to the genus Aspergillus, preferably Aspergillusaculeatus, Aspergillus awamori, Aspergillus fumigatus, Aspergillusfoetidus, Aspergillus japonicus, Aspergillus nidulans, Aspergillusniger, or Aspergillus oryzae; Fusarium, preferably Fusariumbactridioides, Fusarium cerealis, Fusarium crookwellense, Fusariumculmorum, Fusarium graminearum, Fusarium graminum, Fusariumheterosporum, Fusarium negundi, Fusarium oxysporum, Fusariumreticulatum, Fusarium roseum, Fusarium sambucinum, Fusarium sarcochroum,Fusarium sulphureum, Fusarium toruloseum, Fusarium trichothecioides, orFusarium venenatum; Humicola, preferably Humicola insolens or Humicolalanuginosa; or Trichoderma, preferably Trichoderma harzianum,Trichoderma koningii, Trichoderma longibrachiatum, Trichoderma reesei,or Trichoderma viride.

The polypeptide compositions may be prepared in accordance with methodsknown in the art and may be in the form of a liquid or a drycomposition. For instance, the polypeptide composition may be in theform of a granulate or a microgranulate. The polypeptide to be includedin the composition may be stabilized in accordance with methods known inthe art.

Examples are given below of preferred uses of the polypeptidecompositions of the invention. The dosage of the polypeptide compositionof the invention and other conditions under which the composition isused may be determined on the basis of methods known in the art.

Processing of Cellulosic Material

The present invention also relates to methods for degrading orconverting a cellulosic material, comprising: treating the cellulosicmaterial with an enzyme composition in the presence of a polypeptidehaving cellulolytic enhancing activity of the present invention. In apreferred aspect, the method further comprises recovering the degradedor converted cellulosic material.

The present invention also relates to methods of producing afermentation product, comprising: (a) saccharifying a cellulosicmaterial with an enzyme composition in the presence of a polypeptidehaving cellulolytic enhancing activity of the present invention; (b)fermenting the saccharified cellulosic material with one or more(several) fermenting microorganisms to produce the fermentation product;and (c) recovering the fermentation product from the fermentation.

The present invention also relates to methods of fermenting a cellulosicmaterial, comprising: fermenting the cellulosic material with one ormore (several) fermenting microorganisms, wherein the cellulosicmaterial is saccharified with an enzyme composition in the presence of apolypeptide having cellulolytic enhancing activity of the presentinvention. In a preferred aspect, the fermenting of the cellulosicmaterial produces a fermentation product. In another preferred aspect,the method further comprises recovering the fermentation product fromthe fermentation.

The methods of the present invention can be used to saccharify acellulosic material to fermentable sugars and convert the fermentablesugars to many useful substances, e.g., fuel, potable ethanol, and/orfermentation products (e.g., acids, alcohols, ketones, gases, and thelike). The production of a desired fermentation product from cellulosicmaterial typically involves pretreatment, enzymatic hydrolysis(saccharification), and fermentation.

The processing of cellulosic material according to the present inventioncan be accomplished using processes conventional in the art. Moreover,the methods of the present invention can be implemented using anyconventional biomass processing apparatus configured to operate inaccordance with the invention.

Hydrolysis (saccharification) and fermentation, separate orsimultaneous, include, but are not limited to, separate hydrolysis andfermentation (SHF); simultaneous saccharification and fermentation(SSF); simultaneous saccharification and cofermentation (SSCF); hybridhydrolysis and fermentation (HHF); separate hydrolysis andco-fermentation (SHCF); hybrid hydrolysis and fermentation (HHCF); anddirect microbial conversion (DMC). SHF uses separate process steps tofirst enzymatically hydrolyze cellulosic material to fermentable sugars,e.g., glucose, cellobiose, cellotriose, and pentose sugars, and thenferment the fermentable sugars to ethanol. In SSF, the enzymatichydrolysis of cellulosic material and the fermentation of sugars toethanol are combined in one step (Philippidis, G. P., 1996, Cellulosebioconversion technology, in Handbook on Bioethanol: Production andUtilization, Wyman, C. E., ed., Taylor & Francis, Washington, D.C.,179-212). SSCF involves the cofermentation of multiple sugars (Sheehan,J., and Himmel, M., 1999, Enzymes, energy and the environment: Astrategic perspective on the U.S. Department of Energy's research anddevelopment activities for bioethanol, Biotechnol. Prog. 15: 817-827).HHF involves a separate hydrolysis step, and in addition a simultaneoussaccharification and hydrolysis step, which can be carried out in thesame reactor. The steps in an HHF process can be carried out atdifferent temperatures, i.e., high temperature enzymaticsaccharification followed by SSF at a lower temperature that thefermentation strain can tolerate. DMC combines all three processes(enzyme production, hydrolysis, and fermentation) in one or more(several) steps where the same organism is used to produce the enzymesfor conversion of the cellulosic material to fermentable sugars and toconvert the fermentable sugars into a final product (Lynd, L. R.,Weimer, P. J., van Zyl, W. H., and Pretorius, I. S., 2002, Microbialcellulose utilization: Fundamentals and biotechnology, Microbiol. Mol.Biol. Reviews 66: 506-577). It is understood herein that any methodknown in the art comprising pretreatment, enzymatic hydrolysis(saccharification), fermentation, or a combination thereof, can be usedin the practicing the methods of the present invention.

A conventional apparatus can include a fed-batch stirred reactor, abatch stirred reactor, a continuous flow stirred reactor withultrafiltration, and/or a continuous plug-flow column reactor (Fernandade Castilhos Corazza, Flávio Faria de Moraes, Gisella Maria Zanin andIvo Neitzel, 2003, Optimal control in fed-batch reactor for thecellobiose hydrolysis, Acta Scientiarum. Technology 25: 33-38; Gusakov,A. V., and Sinitsyn, A. P., 1985, Kinetics of the enzymatic hydrolysisof cellulose: 1. A mathematical model for a batch reactor process, Enz.Microb. Technol. 7: 346-352), an attrition reactor (Ryu, S. K., and Lee,J. M., 1983, Bioconversion of waste cellulose by using an attritionbioreactor, Biotechnol. Bioeng. 25: 53-65), or a reactor with intensivestirring induced by an electromagnetic field (Gusakov, A. V., Sinitsyn,A. P., Davydkin, I. Y., Davydkin, V. Y., Protas, O. V., 1996,Enhancement of enzymatic cellulose hydrolysis using a novel type ofbioreactor with intensive stirring induced by electromagnetic field,Appl. Biochem. Biotechnol. 56: 141-153). Additional reactor typesinclude: fluidized bed, upflow blanket, immobilized, and extruder typereactors for hydrolysis and/or fermentation.

Pretreatment. In practicing the methods of the present invention, anypretreatment process known in the art can be used to disrupt plant cellwall components of cellulosic material (Chandra et al., 2007, Substratepretreatment: The key to effective enzymatic hydrolysis oflignocellulosics? Adv. Biochem. Engin./Biotechnol. 108: 67-93; Galbe andZacchi, 2007, Pretreatment of lignocellulosic materials for efficientbioethanol production, Adv. Biochem. Engin./Biotechnol. 108: 41-65;Hendriks and Zeeman, 2009, Pretreatments to enhance the digestibility oflignocellulosic biomass, Bioresource Technol. 100: 10-18; Mosier et al.,2005, Features of promising technologies for pretreatment oflignocellulosic biomass, Bioresource Technol. 96: 673-686; Taherzadehand Karimi, 2008, Pretreatment of lignocellulosic wastes to improveethanol and biogas production: A review, Int. J. of Mol. Sci. 9:1621-1651; Yang and Wyman, 2008, Pretreatment: the key to unlockinglow-cost cellulosic ethanol, Biofuels Bioproducts andBiorefining-Biofpr. 2: 26-40).

The cellulosic material can also be subjected to particle sizereduction, pre-soaking, wetting, washing, or conditioning prior topretreatment using methods known in the art.

Conventional pretreatments include, but are not limited to, steampretreatment (with or without explosion), dilute acid pretreatment, hotwater pretreatment, alkaline pretreatment, lime pretreatment, wetoxidation, wet explosion, ammonia fiber explosion, organosolvpretreatment, and biological pretreatment. Additional pretreatmentsinclude ammonia percolation, ultrasound, electroporation, microwave,supercritical CO₂, supercritical H₂O, ozone, and gamma irradiationpretreatments.

The cellulosic material can be pretreated before hydrolysis and/orfermentation. Pretreatment is preferably performed prior to thehydrolysis. Alternatively, the pretreatment can be carried outsimultaneously with enzyme hydrolysis to release fermentable sugars,such as glucose, xylose, and/or cellobiose. In most cases thepretreatment step itself results in some conversion of biomass tofermentable sugars (even in absence of enzymes).

Steam Pretreatment. In steam pretreatment, cellulosic material is heatedto disrupt the plant cell wall components, including lignin,hemicellulose, and cellulose to make the cellulose and other fractions,e.g., hemicellulose, accessible to enzymes. Cellulosic material ispassed to or through a reaction vessel where steam is injected toincrease the temperature to the required temperature and pressure and isretained therein for the desired reaction time. Steam pretreatment ispreferably done at 140-230° C., more preferably 160-200° C., and mostpreferably 170-190° C., where the optimal temperature range depends onany addition of a chemical catalyst. Residence time for the steampretreatment is preferably 1-15 minutes, more preferably 3-12 minutes,and most preferably 4-10 minutes, where the optimal residence timedepends on temperature range and any addition of a chemical catalyst.Steam pretreatment allows for relatively high solids loadings, so thatcellulosic material is generally only moist during the pretreatment. Thesteam pretreatment is often combined with an explosive discharge of thematerial after the pretreatment, which is known as steam explosion, thatis, rapid flashing to atmospheric pressure and turbulent flow of thematerial to increase the accessible surface area by fragmentation (Duffand Murray, 1996, Bioresource Technology 855: 1-33; Galbe and Zacchi,2002, Appl. Microbiol. Biotechnol. 59: 618-628; U.S. Patent ApplicationNo. 20020164730). During steam pretreatment, hemicellulose acetyl groupsare cleaved and the resulting acid autocatalyzes partial hydrolysis ofthe hemicellulose to monosaccharides and oligosaccharides. Lignin isremoved to only a limited extent.

A catalyst such as H₂O₄ or SO₂ (typically 0.3 to 3% w/w) is often addedprior to steam pretreatment, which decreases the time and temperature,increases the recovery, and improves enzymatic hydrolysis (Ballesteroset al., 2006, Appl. Biochem. Biotechnol. 129-132: 496-508; Varga et al.,2004, Appl. Biochem. Biotechnol. 113-116: 509-523; Sassner et al., 2006,Enzyme Microb. Technol. 39: 756-762).

Chemical Pretreatment: The term “chemical treatment” refers to anychemical pretreatment that promotes the separation and/or release ofcellulose, hemicellulose, and/or lignin. Examples of suitable chemicalpretreatment processes include, for example, dilute acid pretreatment,lime pretreatment, wet oxidation, ammonia fiber/freeze explosion (AFEX),ammonia percolation (APR), and organosolv pretreatments.

In dilute acid pretreatment, cellulosic material is mixed with diluteacid, typically H₂SO₄, and water to form a slurry, heated by steam tothe desired temperature, and after a residence time flashed toatmospheric pressure. The dilute acid pretreatment can be performed witha number of reactor designs, e.g., plug-flow reactors, counter-currentreactors, or continuous counter-current shrinking bed reactors (Duff andMurray, 1996, supra; Schell et al., 2004, Bioresource Technol. 91:179-188; Lee et al., 1999, Adv. Biochem. Eng. Biotechnol. 65: 93-115).

Several methods of pretreatment under alkaline conditions can also beused. These alkaline pretreatments include, but are not limited to, limepretreatment, wet oxidation, ammonia percolation (APR), and ammoniafiber/freeze explosion (AFEX).

Lime pretreatment is performed with calcium carbonate, sodium hydroxide,or ammonia at low temperatures of 85-150° C. and residence times from 1hour to several days (Wyman et al., 2005, Bioresource Technol. 96:1959-1966; Mosier et al., 2005, Bioresource Technol. 96: 673-686). WO2006/110891, WO 2006/11899, WO 2006/11900, and WO 2006/110901 disclosepretreatment methods using ammonia.

Wet oxidation is a thermal pretreatment performed typically at 180-200°C. for 5-15 minutes with addition of an oxidative agent such as hydrogenperoxide or over-pressure of oxygen (Schmidt and Thomsen, 1998,Bioresource Technol. 64: 139-151; Palonen et al., 2004, Appl. Biochem.Biotechnol. 117: 1-17; Varga et al., 2004, Biotechnol. Bioeng. 88:567-574; Martin et al., 2006, J. Chem. Technol. Biotechnol. 81:1669-1677). The pretreatment is performed at preferably 1-40% drymatter, more preferably 2-30% dry matter, and most preferably 5-20% drymatter, and often the initial pH is increased by the addition of alkalisuch as sodium carbonate.

A modification of the wet oxidation pretreatment method, known as wetexplosion (combination of wet oxidation and steam explosion), can handledry matter up to 30%. In wet explosion, the oxidizing agent isintroduced during pretreatment after a certain residence time. Thepretreatment is then ended by flashing to atmospheric pressure (WO2006/032282).

Ammonia fiber explosion (AFEX) involves treating cellulosic materialwith liquid or gaseous ammonia at moderate temperatures such as 90-100°C. and high pressure such as 17-20 bar for 5-10 minutes, where the drymatter content can be as high as 60% (Gollapalli et al., 2002, Appl.Biochem. Biotechnol. 98: 23-35; Chundawat et al., 2007, Biotechnol.Bioeng. 96: 219-231; Alizadeh et al., 2005, Appl. Biochem. Biotechnol.121: 1133-1141; Teymouri et al., 2005, Bioresource Technol. 96:2014-2018). AFEX pretreatment results in the depolymerization ofcellulose and partial hydrolysis of hemicellulose. Lignin-carbohydratecomplexes are cleaved.

Organosolv pretreatment delignifies cellulosic material by extractionusing aqueous ethanol (40-60% ethanol) at 160-200° C. for 30-60 minutes(Pan et al., 2005, Biotechnol. Bioeng. 90: 473-481; Pan et al., 2006,Biotechnol. Bioeng. 94: 851-861; Kurabi et al., 2005, Appl. Biochem.Biotechnol. 121: 219-230). Sulphuric acid is usually added as acatalyst. In organosolv pretreatment, the majority of hemicellulose isremoved.

Other examples of suitable pretreatment methods are described by Schellet al., 2003, Appl. Biochem. and Biotechnol. Vol. 105-108, p. 69-85, andMosier et al., 2005, Bioresource Technology 96: 673-686, and U.S.Published Application 2002/0164730.

In one aspect, the chemical pretreatment is preferably carried out as anacid treatment, and more preferably as a continuous dilute and/or mildacid treatment. The acid is typically sulfuric acid, but other acids canalso be used, such as acetic acid, citric acid, nitric acid, phosphoricacid, tartaric acid, succinic acid, hydrogen chloride, or mixturesthereof. Mild acid treatment is conducted in the pH range of preferably1-5, more preferably 1-4, and most preferably 1-3. In one aspect, theacid concentration is in the range from preferably 0.01 to 20 wt % acid,more preferably 0.05 to 10 wt % acid, even more preferably 0.1 to 5 wt %acid, and most preferably 0.2 to 2.0 wt % acid. The acid is contactedwith cellulosic material and held at a temperature in the range ofpreferably 160-220° C., and more preferably 165-195° C., for periodsranging from seconds to minutes to, e.g., 1 second to 60 minutes.

In another aspect, pretreatment is carried out as an ammonia fiberexplosion step (AFEX pretreatment step).

In another aspect, pretreatment takes place in an aqueous slurry. Inpreferred aspects, cellulosic material is present during pretreatment inamounts preferably between 10-80 wt %, more preferably between 20-70 wt%, and most preferably between 30-60 wt %, such as around 50 wt %. Thepretreated cellulosic material can be unwashed or washed using anymethod known in the art, e.g., washed with water.

Mechanical Pretreatment: The term “mechanical pretreatment” refers tovarious types of grinding or milling (e.g., dry milling, wet milling, orvibratory ball milling).

Physical Pretreatment: The term “physical pretreatment” refers to anypretreatment that promotes the separation and/or release of cellulose,hemicellulose, and/or lignin from cellulosic material. For example,physical pretreatment can involve irradiation (e.g., microwaveirradiation), steaming/steam explosion, hydrothermolysis, andcombinations thereof.

Physical pretreatment can involve high pressure and/or high temperature(steam explosion). In one aspect, high pressure means pressure in therange of preferably about 300 to about 600 psi, more preferably about350 to about 550 psi, and most preferably about 400 to about 500 psi,such as around 450 psi. In another aspect, high temperature meanstemperatures in the range of about 100 to about 300° C., preferablyabout 140 to about 235° C. In a preferred aspect, mechanicalpretreatment is performed in a batch-process, steam gun hydrolyzersystem that uses high pressure and high temperature as defined above,e.g., a Sunds Hydrolyzer available from Sunds Defibrator AB, Sweden.

Combined Physical and Chemical Pretreatment: Cellulosic material can bepretreated both physically and chemically. For instance, thepretreatment step can involve dilute or mild acid treatment and hightemperature and/or pressure treatment. The physical and chemicalpretreatments can be carried out sequentially or simultaneously, asdesired. A mechanical pretreatment can also be included.

Accordingly, in a preferred aspect, cellulosic material is subjected tomechanical, chemical, or physical pretreatment, or any combinationthereof, to promote the separation and/or release of cellulose,hemicellulose, and/or lignin.

Biological Pretreatment: The term “biological pretreatment” refers toany biological pretreatment that promotes the separation and/or releaseof cellulose, hemicellulose, and/or lignin from cellulosic material.Biological pretreatment techniques can involve applyinglignin-solubilizing microorganisms (see, for example, Hsu, T.-A., 1996,Pretreatment of biomass, in Handbook on Bioethanol: Production andUtilization, Wyman, C. E., ed., Taylor & Francis, Washington, D.C.,179-212; Ghosh and Singh, 1993, Physicochemical and biologicaltreatments for enzymatic/microbial conversion of cellulosic biomass,Adv. Appl. Microbiol. 39: 295-333; McMillan, J. D., 1994, Pretreatinglignocellulosic biomass: a review, in Enzymatic Conversion of Biomassfor Fuels Production, Himmel, M. E., Baker, J. O., and Overend, R. P.,eds., ACS Symposium Series 566, American Chemical Society, Washington,D.C., chapter 15; Gong, C. S., Cao, N. J., Du, J., and Tsao, G. T.,1999, Ethanol production from renewable resources, in Advances inBiochemical Engineering/Biotechnology, Scheper, T., ed., Springer-VerlagBerlin Heidelberg, Germany, 65: 207-241; Olsson and Hahn-Hagerdal, 1996,Fermentation of lignocellulosic hydrolysates for ethanol production,Enz. Microb. Tech. 18: 312-331; and Vallander and Eriksson, 1990,Production of ethanol from lignocellulosic materials: State of the art,Adv. Biochem. Eng./Biotechnol. 42: 63-95).

Saccharification. In the hydrolysis step, also known assaccharification, the pretreated cellulosic material is hydrolyzed tobreak down cellulose and alternatively also hemicellulose to fermentablesugars, such as glucose, cellobiose, xylose, xylulose, arabinose,mannose, galactose, and/or soluble oligosaccharides. The hydrolysis isperformed enzymatically by an enzyme composition in the presence of apolypeptide having cellulolytic enhancing activity of the presentinvention. The composition can further comprise one or more (several)hemicellulolytic enzymes. The enzymes of the compositions can also beadded sequentially.

Enzymatic hydrolysis is preferably carried out in a suitable aqueousenvironment under conditions that can be readily determined by oneskilled in the art. In a preferred aspect, hydrolysis is performed underconditions suitable for the activity of the enzyme(s), i.e., optimal forthe enzyme(s). The hydrolysis can be carried out as a fed batch orcontinuous process where the pretreated cellulosic material (substrate)is fed gradually to, for example, an enzyme containing hydrolysissolution.

The saccharification is generally performed in stirred-tank reactors orfermentors under controlled pH, temperature, and mixing conditions.Suitable process time, temperature and pH conditions can readily bedetermined by one skilled in the art. For example, the saccharificationcan last up to 200 hours, but is typically performed for preferablyabout 12 to about 96 hours, more preferably about 16 to about 72 hours,and most preferably about 24 to about 48 hours. The temperature is inthe range of preferably about 25° C. to about 70° C., more preferablyabout 30° C. to about 65° C., and more preferably about 40° C. to 60°C., in particular about 50° C. The pH is in the range of preferablyabout 3 to about 8, more preferably about 3.5 to about 7, and mostpreferably about 4 to about 6, in particular about pH 5. The dry solidscontent is in the range of preferably about 5 to about 50 wt %, morepreferably about 10 to about 40 wt %, and most preferably about 20 toabout 30 wt %.

The enzyme composition preferably comprises enzymes having cellulolyticactivity and/or xylan degrading activity. In one aspect, the enzymecomposition comprises one or more (several) cellulolytic enzymes. Inanother aspect, the enzyme composition comprises one or more (several)xylan degrading enzymes. In another aspect, the enzyme compositioncomprises one or more (several) cellulolytic enzymes and one or more(several) xylan degrading enzymes.

The one or more (several) cellulolytic enzymes are preferably selectedfrom the group consisting of an endoglucanase, a cellobiohydrolase, anda beta-glucosidase. The one or more (several) xylan degrading enzymesare preferably selected from the group consisting of a xylanase, anacetyxylan esterase, a feruloyl esterase, an arabinofuranosidase, axylosidase, and a glucuronidase.

In another aspect, the enzyme composition may further or even furthercomprise one or more (several) additional enzyme activities to improvethe degradation of the cellulose-containing material. Preferredadditional enzymes are hemicellulases (e.g., alpha-D-glucuronidases,alpha-L-arabinofuranosidases, endo-mannanases, beta-mannosidases,alpha-galactosidases, endo-alpha-L-arabinanases, beta-galactosidases),carbohydrate-esterases (e.g., acetyl-xylan esterases, acetyl-mannanesterases, ferulic acid esterases, coumaric acid esterases, glucuronoylesterases), pectinases, proteases, ligninolytic enzymes (e.g., laccases,manganese peroxidases, lignin peroxidases, H₂O₂-producing enzymes,oxidoreductases), expansins, swollenins, or mixtures thereof. In themethods of the present invention, the additional enzyme(s) can be addedprior to or during fermentation, e.g., during saccharification or duringor after propagation of the fermenting microorganism(s).

One or more (several) components of the enzyme composition may bewild-type proteins, recombinant proteins, or a combination of wild-typeproteins and recombinant proteins. For example, one or more (several)components may be native proteins of a cell, which is used as a hostcell to express recombinantly one or more (several) other components ofthe enzyme composition. One or more (several) components of the enzymecomposition may be produced as monocomponents, which are then combinedto form the enzyme composition. The enzyme composition may be acombination of multicomponent and monocomponent protein preparations.

The enzymes used in the methods of the present invention may be in anyform suitable for use in the processes described herein, such as, forexample, a crude fermentation broth with or without cells removed, asemi-purified or purified enzyme preparation, or a host cell as a sourceof the enzymes. The enzyme composition may be a dry powder or granulate,a non-dusting granulate, a liquid, a stabilized liquid, or a stabilizedprotected enzyme. Liquid enzyme preparations may, for instance, bestabilized by adding stabilizers such as a sugar, a sugar alcohol oranother polyol, and/or lactic acid or another organic acid according toestablished processes.

The optimum amounts of the enzymes and polypeptides having cellulolyticenhancing activity depend on several factors including, but not limitedto, the mixture of component cellulolytic enzymes, the cellulosicsubstrate, the concentration of cellulosic substrate, thepretreatment(s) of the cellulosic substrate, temperature, time, pH, andinclusion of fermenting organism (e.g., yeast for SimultaneousSaccharification and Fermentation).

In a preferred aspect, an effective amount of cellulolytic enzyme(s) tocellulosic material is about 0.5 to about 50 mg, preferably at about 0.5to about 40 mg, more preferably at about 0.5 to about 25 mg, morepreferably at about 0.75 to about 20 mg, more preferably at about 0.75to about 15 mg, even more preferably at about 0.5 to about 10 mg, andmost preferably at about 2.5 to about 10 mg per g of cellulosicmaterial.

In another preferred aspect, an effective amount of polypeptide(s)having cellulolytic enhancing activity to cellulosic material is about0.01 to about 50.0 mg, preferably about 0.01 to about 40 mg, morepreferably about 0.01 to about 30 mg, more preferably about 0.01 toabout 20 mg, more preferably about 0.01 to about 10 mg, more preferablyabout 0.01 to about 5 mg, more preferably at about 0.025 to about 1.5mg, more preferably at about 0.05 to about 1.25 mg, more preferably atabout 0.075 to about 1.25 mg, more preferably at about 0.1 to about 1.25mg, even more preferably at about 0.15 to about 1.25 mg, and mostpreferably at about 0.25 to about 1.0 mg per g of cellulosic material.

In another preferred aspect, an effective amount of polypeptide(s)having cellulolytic enhancing activity to cellulolytic enzyme(s) isabout 0.005 to about 1.0 g, preferably at about 0.01 to about 1.0 g,more preferably at about 0.15 to about 0.75 g, more preferably at about0.15 to about 0.5 g, more preferably at about 0.1 to about 0.5 g, evenmore preferably at about 0.1 to about 0.5 g, and most preferably atabout 0.05 to about 0.2 g per g of cellulolytic enzyme(s).

The enzymes can be derived or obtained from any suitable origin,including, bacterial, fungal, yeast, plant, or mammalian origin. Theterm “obtained” means herein that the enzyme may have been isolated froman organism that naturally produces the enzyme as a native enzyme. Theterm “obtained” also means herein that the enzyme may have been producedrecombinantly in a host organism employing methods described herein,wherein the recombinantly produced enzyme is either native or foreign tothe host organism or has a modified amino acid sequence, e.g., havingone or more (several) amino acids that are deleted, inserted and/orsubstituted, i.e., a recombinantly produced enzyme that is a mutantand/or a fragment of a native amino acid sequence or an enzyme producedby nucleic acid shuffling processes known in the art. Encompassed withinthe meaning of a native enzyme are natural variants and within themeaning of a foreign enzyme are variants obtained recombinantly, such asby site-directed mutagenesis or shuffling.

A polypeptide having cellulolytic enzyme activity or xylan degradingactivity may be a bacterial polypeptide. For example, the polypeptidemay be a gram positive bacterial polypeptide such as a Bacillus,Streptococcus, Streptomyces, Staphylococcus, Enterococcus,Lactobacillus, Lactococcus, Clostridium, Geobacillus, or Oceanobacilluspolypeptide having cellulolytic enzyme activity or xylan degradingactivity, or a Gram negative bacterial polypeptide such as an E. coli,Pseudomonas, Salmonella, Campylobacter, Helicobacter, Flavobacterium,Fusobacterium, Ilyobacter, Neisseria, or Ureaplasma polypeptide havingcellulolytic enzyme activity or xylan degrading activity.

In a preferred aspect, the polypeptide is a Bacillus alkalophilus,Bacillus amyloliquefaciens, Bacillus brevis, Bacillus circulans,Bacillus clausii, Bacillus coagulans, Bacillus firmus, Bacillus lautus,Bacillus lentus, Bacillus licheniformis, Bacillus megaterium, Bacilluspumilus, Bacillus stearothermophilus, Bacillus subtilis, or Bacillusthuringiensis polypeptide having cellulolytic enzyme activity or xylandegrading activity.

In another preferred aspect, the polypeptide is a Streptococcusequisimilis, Streptococcus pyogenes, Streptococcus uberis, orStreptococcus equi subsp. Zooepidemicus polypeptide having cellulolyticenzyme activity or xylan degrading activity.

In another preferred aspect, the polypeptide is a Streptomycesachromogenes, Streptomyces avermitilis, Streptomyces coelicolor,Streptomyces griseus, or Streptomyces lividans polypeptide havingcellulolytic enzyme activity or xylan degrading activity.

The polypeptide having cellulolytic enzyme activity or xylan degradingactivity may also be a fungal polypeptide, and more preferably a yeastpolypeptide such as a Candida, Kluyveromyces, Pichia, Saccharomyces,Schizosaccharomyces, or Yarrowia polypeptide having cellulolytic enzymeactivity or xylan degrading activity; or more preferably a filamentousfungal polypeptide such as an Acremonium, Agaricus, Alternaria,Aspergillus, Aureobasidium, Botryospaeria, Ceriporiopsis, Chaetomidium,Chrysosporium, Claviceps, Cochliobolus, Coprinopsis, Coptotermes,Corynascus, Cryphonectria, Cryptococcus, Diplodia, Exidia, Filibasidium,Fusarium, Gibberella, Holomastigotoides, Humicola, Irpex, Lentinula,Leptospaeria, Magnaporthe, Melanocarpus, Meripilus, Mucor,Myceliophthora, Neocallimastix, Neurospora, Paecilomyces, Penicillium,Phanerochaete, Piromyces, Poitrasia, Pseudoplectania,Pseudotrichonympha, Rhizomucor, Schizophyllum, Scytalidium, Talaromyces,Thermoascus, Thielavia, Tolypocladium, Trichoderma, Trichophaea,Verticillium, Volvariella, or Xylaria polypeptide having cellulolyticenzyme activity or xylan degrading activity.

In a preferred aspect, the polypeptide is a Saccharomycescarlsbergensis, Saccharomyces cerevisiae, Saccharomyces diastaticus,Saccharomyces douglasii, Saccharomyces kluyveri, Saccharomycesnorbensis, or Saccharomyces oviformis polypeptide having cellulolyticenzyme activity or xylan degrading activity.

In another preferred aspect, the polypeptide is an Acremoniumcellulolyticus, Aspergillus aculeatus, Aspergillus awamori, Aspergillusfumigatus, Aspergillus foetidus, Aspergillus japonicus, Aspergillusnidulans, Aspergillus niger, Aspergillus oryzae, Chrysosporiumkeratinophilum, Chrysosporium lucknowense, Chrysosporium tropicum,Chrysosporium merdarium, Chrysosporium inops, Chrysosporium pannicola,Chrysosporium queenslandicum, Chrysosporium zonatum, Fusariumbactridioides, Fusarium cerealis, Fusarium crookwellense, Fusariumculmorum, Fusarium graminearum, Fusarium graminum, Fusariumheterosporum, Fusarium negundi, Fusarium oxysporum, Fusariumreticulatum, Fusarium roseum, Fusarium sambucinum, Fusarium sarcochroum,Fusarium sporotrichioides, Fusarium sulphureum, Fusarium torulosum,Fusarium trichothecioides, Fusarium venenatum, Humicola grisea, Humicolainsolens, Humicola lanuginosa, Irpex lacteus, Mucor miehei,Myceliophthora thermophila, Neurospora crassa, Penicillium funiculosum,Penicillium purpurogenum, Phanerochaete chrysosporium, Thielaviaachromatica, Thielavia albomyces, Thielavia albopilosa, Thielaviaaustraleinsis, Thielavia fimeti, Thielavia microspora, Thielaviaovispora, Thielavia peruviana, Thielavia spededonium, Thielavia setosa,Thielavia subthermophila, Thielavia terrestris, Trichoderma harzianum,Trichoderma koningii, Trichoderma longibrachiatum, Trichoderma reesei,Trichoderma viride, or Trichophaea saccata polypeptide havingcellulolytic enzyme activity or xylan degrading activity.

Chemically modified or protein engineered mutants of polypeptides havingcellulolytic enzyme activity or xylan degrading activity may also beused.

One or more (several) components of the enzyme composition may be arecombinant component, i.e., produced by cloning of a DNA sequenceencoding the single component and subsequent cell transformed with theDNA sequence and expressed in a host (see, for example, WO 91/17243 andWO 91/17244). The host is preferably a heterologous host (enzyme isforeign to host), but the host may under certain conditions also be ahomologous host (enzyme is native to host). Monocomponent cellulolyticproteins may also be prepared by purifying such a protein from afermentation broth.

Examples of commercial cellulolytic protein preparations suitable foruse in the present invention include, for example, CELLIC™ Ctec(Novozymes A/S), CELLUCLAST™ (Novozymes A/S), NOVOZYM™ 188 (NovozymesA/S), CELLUZYME™ (Novozymes A/S), CEREFLO™ (Novozymes A/S), andULTRAFLO™ (Novozymes A/S), ACCELERASE™ (Genencor Int.), LAMINEX™(Genencor Int.), SPEZYME™ CP (Genencor Int.), ROHAMENT™ 7069 W (RöhmGmbH), FIBREZYME® LDI (Dyadic International, Inc.), FIBREZYME® LBR(Dyadic International, Inc.), or VISCOSTAR® 150L (Dyadic International,Inc.). The cellulase enzymes are added in amounts effective from about0.001 to about 5.0 wt % of solids, more preferably from about 0.025 toabout 4.0 wt % of solids, and most preferably from about 0.005 to about2.0 wt % of solids. The cellulase enzymes are added in amounts effectivefrom about 0.001 to about 5.0 wt % of solids, more preferably from about0.025 to about 4.0 wt % of solids, and most preferably from about 0.005to about 2.0 wt % of solids.

Examples of bacterial endoglucanases that can be used in the methods ofthe present invention, include, but are not limited to, an Acidothermuscellulolyticus endoglucanase (WO 91/05039; WO 93/15186; U.S. Pat. No.5,275,944; WO 96/02551; U.S. Pat. No. 5,536,655, WO 00/70031, WO05/093050); Thermobifida fusca endoglucanase III (WO 05/093050); andThermobifida fusca endoglucanase V (WO 05/093050).

Examples of fungal endoglucanases that can be used in the methods of thepresent invention, include, but are not limited to, a Trichoderma reeseiendoglucanase I (Penttila et al., 1986, Gene 45: 253-263; GENBANK™accession no. M15665); Trichoderma reesei endoglucanase II (Saloheimo,et al., 1988, Gene 63:11-22; GENBANK™ accession no. M19373); Trichodermareesei endoglucanase III (Okada et al., 1988, Appl. Environ. Microbiol.64: 555-563; GENBANK™ accession no. AB003694); Trichoderma reeseiendoglucanase IV (Saloheimo et al., 1997, Eur. J. Biochem. 249: 584-591;GENBANK™ accession no. Y11113); and Trichoderma reesei endoglucanase V(Saloheimo et al., 1994, Molecular Microbiology 13: 219-228; GENBANK™accession no. Z33381); Aspergillus aculeatus endoglucanase (Ooi et al.,1990, Nucleic Acids Research 18: 5884); Aspergillus kawachiiendoglucanase (Sakamoto et al., 1995, Current Genetics 27: 435-439);Erwinia carotovara endoglucanase (Saarilahti et al., 1990, Gene 90:9-14); Fusarium oxysporum endoglucanase (GENBANK™ accession no. L29381);Humicola grisea var. thermoidea endoglucanase (GENBANK™ accession no.AB003107); Melanocarpus albomyces endoglucanase (GENBANK™ accession no.MAL515703); Neurospora crassa endoglucanase (GENBANK™ accession no.XM_(—)324477); Humicola insolens endoglucanase V; Myceliophthorathermophila CBS 117.65 endoglucanase; basidiomycete CBS 495.95endoglucanase; basidiomycete CBS 494.95 endoglucanase; Thielaviaterrestris NRRL 8126 CEL6B endoglucanase; Thielavia terrestris NRRL 8126CEL6C endoglucanase); Thielavia terrestris NRRL 8126 CEL7Cendoglucanase; Thielavia terrestris NRRL 8126 CEL7E endoglucanase;Thielavia terrestris NRRL 8126 CEL7F endoglucanase; Cladorrhinumfoecundissimum ATCC 62373 CEL7A endoglucanase; and Trichoderma reeseistrain No. VTT-D-80133 endoglucanase (GENBANK™ accession no. M15665).

Examples of cellobiohydrolases useful in the methods of the presentinvention include, but are not limited to, Trichoderma reeseicellobiohydrolase I; Trichoderma reesei cellobiohydrolase II; Humicolainsolens cellobiohydrolase I, Myceliophthora thermophilacellobiohydrolase II, Thielavia terrestris cellobiohydrolase II (CEL6A),Chaetomium thermophilum cellobiohydrolase I, and Chaetomium thermophilumcellobiohydrolase II.

Examples of beta-glucosidases useful in the methods of the presentinvention include, but are not limited to, Aspergillus oryzaebeta-glucosidase; Aspergillus fumigatus beta-glucosidase; Penicilliumbrasilianum IBT 20888 beta-glucosidase; Aspergillus nigerbeta-glucosidase; and Aspergillus aculeatus beta-glucosidase.

The Aspergillus oryzae polypeptide having beta-glucosidase activity canbe obtained according to WO 2002/095014. The Aspergillus fumigatuspolypeptide having beta-glucosidase activity can be obtained accordingto WO 2005/047499. The Penicillium brasilianum polypeptide havingbeta-glucosidase activity can be obtained according to WO 2007/019442.The Aspergillus niger polypeptide having beta-glucosidase activity canbe obtained according to Dan et al., 2000, J. Biol. Chem. 275:4973-4980. The Aspergillus aculeatus polypeptide having beta-glucosidaseactivity can be obtained according to Kawaguchi et al., 1996, Gene 173:287-288.

The beta-glucosidase may be a fusion protein. In one aspect, thebeta-glucosidase is the Aspergillus oryzae beta-glucosidase variant BGfusion protein or the Aspergillus oryzae beta-glucosidase fusion proteinobtained according to WO 2008/057637.

Other endoglucanases, cellobiohydrolases, and beta-glucosidases aredisclosed in numerous Glycosyl Hydrolase families using theclassification according to Henrissat B., 1991, A classification ofglycosyl hydrolases based on amino-acid sequence similarities, Biochem.J. 280: 309-316, and Henrissat B., and Bairoch A., 1996, Updating thesequence-based classification of glycosyl hydrolases, Biochem. J. 316:695-696.

Other cellulolytic enzymes that may be used in the present invention aredescribed in EP 495,257, EP 531,315, EP 531,372, WO 89/09259, WO94/07998, WO 95/24471, WO 96/11262, WO 96/29397, WO 96/034108, WO97/14804, WO 98/08940, WO 98/012307, WO 98/13465, WO 98/015619, WO98/015633, WO 98/028411, WO 99/06574, WO 99/10481, WO 99/025846, WO99/025847, WO 99/031255, WO 2000/009707, WO 2002/050245, WO2002/0076792, WO 2002/101078, WO 2003/027306, WO 2003/052054, WO2003/052055, WO 2003/052056, WO 2003/052057, WO 2003/052118, WO2004/016760, WO 2004/043980, WO 2004/048592, WO 2005/001065, WO2005/028636, WO 2005/093050, WO 2005/093073, WO 2006/074005, WO2006/117432, WO 2007/071818, WO 2007/071820, WO 2008/008070, WO2008/008793, U.S. Pat. No. 4,435,307, U.S. Pat. No. 5,457,046, U.S. Pat.No. 5,648,263, U.S. Pat. No. 5,686,593, U.S. Pat. No. 5,691,178, U.S.Pat. No. 5,763,254, and U.S. Pat. No. 5,776,757.

Examples of commercial xylan degrading enzyme preparations suitable foruse in the present invention include, for example, SHEARZYME™ (NovozymesA/S), CELLIC™ Htec (Novozymes A/S), VISCOZYME® (Novozymes A/S),ULTRAFLO® (Novozymes A/S), PULPZYME® HC (Novozymes A/S), MULTIFECT®Xylanase (Genencor), ECOPULP® TX-200A (AB Enzymes), HSP 6000 Xylanase(DSM), DEPOL™ 333P (Biocatalysts Limit, Wales, UK), DEPOL™ 740L.(Biocatalysts Limit, Wales, UK), and DEPOL™ 762P (Biocatalysts Limit,Wales, UK).

Examples of xylanases useful in the methods of the present inventioninclude, but are not limited to, Aspergillus aculeatus xylanase(GeneSeqP:AAR63790; WO 94/21785), Aspergillus fumigatus xylanases (WO2006/078256), and Thielavia terrestris NRRL 8126 xylanases (WO2009/079210).

Examples of beta-xylosidases useful in the methods of the presentinvention include, but are not limited to, Trichoderma reeseibeta-xylosidase (UniProtKB/TrEMBL accession number Q92458), Talaromycesemersonii (SwissProt accession number Q8×212), and Neurospora crassa(SwissProt accession number Q7SOW4).

Examples of acetylxylan esterases useful in the methods of the presentinvention include, but are not limited to, Hypocrea jecorina acetylxylanesterase (WO 2005/001036), Neurospora crassa acetylxylan esterase(UniProt accession number q7s259), Thielavia terrestris NRRL 8126acetylxylan esterase (WO 2009/042846), Chaetomium globosum acetylxylanesterase (Uniprot accession number Q2GWX4), Chaetomium gracileacetylxylan esterase (GeneSeqP accession number AAB82124), Phaeosphaerianodorum acetylxylan esterase (Uniprot accession number Q0UHJ1), andHumicola insolens DSM 1800 acetylxylan esterase (WO 2009/073709).

Examples of ferulic acid esterases useful in the methods of the presentinvention include, but are not limited to, Humicola insolens DSM 1800feruloyl esterase (WO 2009/076122), Neurospora crassa feruloyl esterase(UniProt accession number Q9HGR3), and Neosartorya fischeri feruloylesterase (UniProt Accession number A1D9T4).

Examples of arabinofuranosidases useful in the methods of the presentinvention include, but are not limited to, Humicola insolens DSM 1800arabinofuranosidase (WO 2009/073383) and Aspergillus nigerarabinofuranosidase (GeneSeqP accession number AAR94170).

Examples of alpha-glucuronidases useful in the methods of the presentinvention include, but are not limited to, Aspergillus clavatusalpha-glucuronidase (UniProt accession number alcc12), Trichodermareesei alpha-glucuronidase (Uniprot accession number Q99024),Talaromyces emersonii alpha-glucuronidase (UniProt accession numberQ8×211), Aspergillus niger alpha-glucuronidase (Uniprot accession numberQ96WX9), Aspergillus terreus alpha-glucuronidase (SwissProt accessionnumber Q0CJP9), and Aspergillus fumigatus alpha-glucuronidase (SwissProtaccession number Q4WW45).

The enzymes and proteins used in the methods of the present inventionmay be produced by fermentation of the above-noted microbial strains ona nutrient medium containing suitable carbon and nitrogen sources andinorganic salts, using procedures known in the art (see, e.g., Bennett,J. W. and LaSure, L. (eds.), More Gene Manipulations in Fungi, AcademicPress, CA, 1991). Suitable media are available from commercial suppliersor may be prepared according to published compositions (e.g., incatalogues of the American Type Culture Collection). Temperature rangesand other conditions suitable for growth and enzyme production are knownin the art (see, e.g., Bailey, J. E., and Ollis, D. F., BiochemicalEngineering Fundamentals, McGraw-Hill Book Company, NY, 1986).

The fermentation can be any method of cultivation of a cell resulting inthe expression or isolation of an enzyme. Fermentation may, therefore,be understood as comprising shake flask cultivation, or small- orlarge-scale fermentation (including continuous, batch, fed-batch, orsolid state fermentations) in laboratory or industrial fermentorsperformed in a suitable medium and under conditions allowing the enzymeto be expressed or isolated. The resulting enzymes produced by themethods described above may be recovered from the fermentation mediumand purified by conventional procedures.

Fermentation. The fermentable sugars obtained from the pretreated andhydrolyzed cellulosic material can be fermented by one or more (several)fermenting microorganisms capable of fermenting the sugars directly orindirectly into a desired fermentation product. “Fermentation” or“fermentation process” refers to any fermentation process or any processcomprising a fermentation step. Fermentation processes also includefermentation processes used in the consumable alcohol industry (e.g.,beer and wine), dairy industry (e.g., fermented dairy products), leatherindustry, and tobacco industry. The fermentation conditions depend onthe desired fermentation product and fermenting organism and can easilybe determined by one skilled in the art.

In the fermentation step, sugars, released from cellulosic material as aresult of the pretreatment and enzymatic hydrolysis steps, are fermentedto a product, e.g., ethanol, by a fermenting organism, such as yeast.Hydrolysis (saccharification) and fermentation can be separate orsimultaneous, as described herein.

Any suitable hydrolyzed cellulosic material can be used in thefermentation step in practicing the present invention. The material isgenerally selected based on the desired fermentation product, i.e., thesubstance to be obtained from the fermentation, and the processemployed, as is well known in the art.

The term “fermentation medium” is understood herein to refer to a mediumbefore the fermenting microorganism(s) is(are) added, such as, a mediumresulting from a saccharification process, as well as a medium used in asimultaneous saccharification and fermentation process (SSF).

“Fermenting microorganism” refers to any microorganism, includingbacterial and fungal organisms, suitable for use in a desiredfermentation process to produce a fermentation product. The fermentingorganism can be C₆ and/or C₅ fermenting organisms, or a combinationthereof. Both C₆ and C₅ fermenting organisms are well known in the art.Suitable fermenting microorganisms are able to ferment, i.e., convert,sugars, such as glucose, xylose, xylulose, arabinose, maltose, mannose,galactose, or oligosaccharides, directly or indirectly into the desiredfermentation product.

Examples of bacterial and fungal fermenting organisms producing ethanolare described by Lin et al., 2006, Appl. Microbiol. Biotechnol. 69:627-642.

Examples of fermenting microorganisms that can ferment C6 sugars includebacterial and fungal organisms, such as yeast. Preferred yeast includesstrains of the Saccharomyces spp., preferably Saccharomyces cerevisiae.

Examples of fermenting organisms that can ferment C5 sugars includebacterial and fungal organisms, such as yeast. Preferred C5 fermentingyeast include strains of Pichia, preferably Pichia stipitis, such asPichia stipitis CBS 5773; strains of Candida, preferably Candidaboidinii, Candida brassicae, Candida sheatae, Candida diddensii, Candidapseudotropicalis, or Candida utilis.

Other fermenting organisms include strains of Zymomonas, such asZymomonas mobilis; Hansenula, such as Hansenula anomala; Kluyveromyces,such as K. fragilis; Schizosaccharomyces, such as S. pombe; and E. coli,especially E. coli strains that have been genetically modified toimprove the yield of ethanol.

In a preferred aspect, the yeast is a Saccharomyces spp. In a morepreferred aspect, the yeast is Saccharomyces cerevisiae. In another morepreferred aspect, the yeast is Saccharomyces distaticus. In another morepreferred aspect, the yeast is Saccharomyces uvarum. In anotherpreferred aspect, the yeast is a Kluyveromyces. In another morepreferred aspect, the yeast is Kluyveromyces marxianus. In another morepreferred aspect, the yeast is Kluyveromyces fragilis. In anotherpreferred aspect, the yeast is a Candida. In another more preferredaspect, the yeast is Candida boidinii. In another more preferred aspect,the yeast is Candida brassicae. In another more preferred aspect, theyeast is Candida diddensii. In another more preferred aspect, the yeastis Candida pseudotropicalis. In another more preferred aspect, the yeastis Candida utilis. In another preferred aspect, the yeast is aClavispora. In another more preferred aspect, the yeast is Clavisporalusitaniae. In another more preferred aspect, the yeast is Clavisporaopuntiae. In another preferred aspect, the yeast is a Pachysolen. Inanother more preferred aspect, the yeast is Pachysolen tannophilus. Inanother preferred aspect, the yeast is a Pichia. In another morepreferred aspect, the yeast is a Pichia stipitis. In another preferredaspect, the yeast is a Bretannomyces. In another more preferred aspect,the yeast is Bretannomyces clausenii (Philippidis, G. P., 1996,Cellulose bioconversion technology, in Handbook on Bioethanol:Production and Utilization, Wyman, C. E., ed., Taylor & Francis,Washington, D.C., 179-212).

Bacteria that can efficiently ferment hexose and pentose to ethanolinclude, for example, Zymomonas mobilis and Clostridium thermocellum(Philippidis, 1996, supra).

In a preferred aspect, the bacterium is a Zymomonas. In a more preferredaspect, the bacterium is Zymomonas mobilis. In another preferred aspect,the bacterium is a Clostridium. In another more preferred aspect, thebacterium is Clostridium thermocellum.

Commercially available yeast suitable for ethanol production includes,e.g., ETHANOL RED™ yeast (available from Fermentis/Lesaffre, USA), FALI™(available from Fleischmann's Yeast, USA), SUPERSTART™ and THERMOSACC™fresh yeast (available from Ethanol Technology, WI, USA), BIOFERM™ AFTand XR (available from NABC—North American Bioproducts Corporation, GA,USA), GERT STRAND™ (available from Gert Strand AB, Sweden), and FERMIOL™(available from DSM Specialties).

In a preferred aspect, the fermenting microorganism has been geneticallymodified to provide the ability to ferment pentose sugars, such asxylose utilizing, arabinose utilizing, and xylose and arabinoseco-utilizing microorganisms.

The cloning of heterologous genes into various fermenting microorganismshas led to the construction of organisms capable of converting hexosesand pentoses to ethanol (cofermentation) (Chen and Ho, 1993, Cloning andimproving the expression of Pichia stipitis xylose reductase gene inSaccharomyces cerevisiae, Appl. Biochem. Biotechnol. 39-40: 135-147; Hoet al., 1998, Genetically engineered Saccharomyces yeast capable ofeffectively cofermenting glucose and xylose, Appl. Environ. Microbiol.64: 1852-1859; Kotter and Ciriacy, 1993, Xylose fermentation bySaccharomyces cerevisiae, Appl. Microbiol. Biotechnol. 38: 776-783;Walfridsson et al., 1995, Xylose-metabolizing Saccharomyces cerevisiaestrains overexpressing the TKL1 and TAL1 genes encoding the pentosephosphate pathway enzymes transketolase and transaldolase, Appl.Environ. Microbiol. 61: 4184-4190; Kuyper et al., 2004, Minimalmetabolic engineering of Saccharomyces cerevisiae for efficientanaerobic xylose fermentation: a proof of principle, FEMS Yeast Research4: 655-664; Beall et al., 1991, Parametric studies of ethanol productionfrom xylose and other sugars by recombinant Escherichia coli, Biotech.Bioeng. 38: 296-303; Ingram et al., 1998, Metabolic engineering ofbacteria for ethanol production, Biotechnol. Bioeng. 58: 204-214; Zhanget al., 1995, Metabolic engineering of a pentose metabolism pathway inethanologenic Zymomonas mobilis, Science 267: 240-243; Deanda et al.,1996, Development of an arabinose-fermenting Zymomonas mobilis strain bymetabolic pathway engineering, Appl. Environ. Microbiol. 62: 4465-4470;WO 2003/062430, xylose isomerase).

In a preferred aspect, the genetically modified fermenting microorganismis Saccharomyces cerevisiae. In another preferred aspect, thegenetically modified fermenting microorganism is Zymomonas mobilis. Inanother preferred aspect, the genetically modified fermentingmicroorganism is Escherichia coli. In another preferred aspect, thegenetically modified fermenting microorganism is Klebsiella oxytoca. Inanother preferred aspect, the genetically modified fermentingmicroorganism is Kluyveromyces sp.

It is well known in the art that the organisms described above can alsobe used to produce other substances, as described herein.

The fermenting microorganism is typically added to the degradedlignocellulose or hydrolysate and the fermentation is performed forabout 8 to about 96 hours, such as about 24 to about 60 hours. Thetemperature is typically between about 26° C. to about 60° C., inparticular about 32° C. or 50° C., and at about pH 3 to about pH 8, suchas around pH 4-5, 6, or 7.

In a preferred aspect, the yeast and/or another microorganism is appliedto the degraded cellulosic material and the fermentation is performedfor about 12 to about 96 hours, such as typically 24-60 hours. In apreferred aspect, the temperature is preferably between about 20° C. toabout 60° C., more preferably about 25° C. to about 50° C., and mostpreferably about 32° C. to about 50° C., in particular about 32° C. or50° C., and the pH is generally from about pH 3 to about pH 7,preferably around pH 4-7. However, some fermenting organisms, e.g.,bacteria, have higher fermentation temperature optima. Yeast or anothermicroorganism is preferably applied in amounts of approximately 10⁵ to10¹², preferably from approximately 10⁷ to 10¹⁰, especiallyapproximately 2×10⁸ viable cell count per ml of fermentation broth.Further guidance in respect of using yeast for fermentation can be foundin, e.g., “The Alcohol Textbook” (Editors K. Jacques, T. P. Lyons and D.R. Kelsall, Nottingham University Press, United Kingdom 1999), which ishereby incorporated by reference.

For ethanol production, following the fermentation the fermented slurryis distilled to extract the ethanol. The ethanol obtained according tothe methods of the invention can be used as, e.g., fuel ethanol,drinking ethanol, i.e., potable neutral spirits, or industrial ethanol.

A fermentation stimulator can be used in combination with any of theprocesses described herein to further improve the fermentation process,and in particular, the performance of the fermenting microorganism, suchas, rate enhancement and ethanol yield. A “fermentation stimulator”refers to stimulators for growth of the fermenting microorganisms, inparticular, yeast. Preferred fermentation stimulators for growth includevitamins and minerals. Examples of vitamins include multivitamins,biotin, pantothenate, nicotinic acid, meso-inositol, thiamine,pyridoxine, para-aminobenzoic acid, folic acid, riboflavin, and VitaminsA, B, C, D, and E. See, for example, Alfenore et al., Improving ethanolproduction and viability of Saccharomyces cerevisiae by a vitaminfeeding strategy during fed-batch process, Springer-Verlag (2002), whichis hereby incorporated by reference. Examples of minerals includeminerals and mineral salts that can supply nutrients comprising P, K,Mg, S, Ca, Fe, Zn, Mn, and Cu.

Fermentation products: A fermentation product can be any substancederived from the fermentation. The fermentation product can be, withoutlimitation, an alcohol (e.g., arabinitol, butanol, ethanol, glycerol,methanol, 1,3-propanediol, sorbitol, and xylitol); an organic acid(e.g., acetic acid, acetonic acid, adipic acid, ascorbic acid, citricacid, 2,5-diketo-D-gluconic acid, formic acid, fumaric acid, glucaricacid, gluconic acid, glucuronic acid, glutaric acid, 3-hydroxypropionicacid, itaconic acid, lactic acid, malic acid, malonic acid, oxalic acid,propionic acid, succinic acid, and xylonic acid); a ketone (e.g.,acetone); an amino acid (e.g., aspartic acid, glutamic acid, glycine,lysine, serine, and threonine); and a gas (e.g., methane, hydrogen (H₂),carbon dioxide (CO₂), and carbon monoxide (CO)). The fermentationproduct can also be protein as a high value product.

In a preferred aspect, the fermentation product is an alcohol. It willbe understood that the term “alcohol” encompasses a substance thatcontains one or more hydroxyl moieties. In a more preferred aspect, thealcohol is arabinitol. In another more preferred aspect, the alcohol isbutanol. In another more preferred aspect, the alcohol is ethanol. Inanother more preferred aspect, the alcohol is glycerol. In another morepreferred aspect, the alcohol is methanol. In another more preferredaspect, the alcohol is 1,3-propanediol. In another more preferredaspect, the alcohol is sorbitol. In another more preferred aspect, thealcohol is xylitol. See, for example, Gong, C. S., Cao, N. J., Du, J.,and Tsao, G. T., 1999, Ethanol production from renewable resources, inAdvances in Biochemical Engineering/Biotechnology, Scheper, T., ed.,Springer-Verlag Berlin Heidelberg, Germany, 65: 207-241; Silveira, M.M., and Jonas, R., 2002, The biotechnological production of sorbitol,Appl. Microbiol. Biotechnol. 59: 400-408; Nigam, P., and Singh, D.,1995, Processes for fermentative production of xylitol—a sugarsubstitute, Process Biochemistry 30 (2): 117-124; Ezeji, T. C., Qureshi,N. and Blaschek, H. P., 2003, Production of acetone, butanol and ethanolby Clostridium beijerinckii BA101 and in situ recovery by gas stripping,World Journal of Microbiology and Biotechnology 19 (6): 595-603.

In another preferred aspect, the fermentation product is an organicacid. In another more preferred aspect, the organic acid is acetic acid.In another more preferred aspect, the organic acid is acetonic acid. Inanother more preferred aspect, the organic acid is adipic acid. Inanother more preferred aspect, the organic acid is ascorbic acid. Inanother more preferred aspect, the organic acid is citric acid. Inanother more preferred aspect, the organic acid is 2,5-diketo-D-gluconicacid. In another more preferred aspect, the organic acid is formic acid.In another more preferred aspect, the organic acid is fumaric acid. Inanother more preferred aspect, the organic acid is glucaric acid. Inanother more preferred aspect, the organic acid is gluconic acid. Inanother more preferred aspect, the organic acid is glucuronic acid. Inanother more preferred aspect, the organic acid is glutaric acid. Inanother preferred aspect, the organic acid is 3-hydroxypropionic acid.In another more preferred aspect, the organic acid is itaconic acid. Inanother more preferred aspect, the organic acid is lactic acid. Inanother more preferred aspect, the organic acid is malic acid. Inanother more preferred aspect, the organic acid is malonic acid. Inanother more preferred aspect, the organic acid is oxalic acid. Inanother more preferred aspect, the organic acid is propionic acid. Inanother more preferred aspect, the organic acid is succinic acid. Inanother more preferred aspect, the organic acid is xylonic acid. See,for example, Chen, R., and Lee, Y. Y., 1997, Membrane-mediatedextractive fermentation for lactic acid production from cellulosicbiomass, Appl. Biochem. Biotechnol. 63-65: 435-448.

In another preferred aspect, the fermentation product is a ketone. Itwill be understood that the term “ketone” encompasses a substance thatcontains one or more ketone moieties. In another more preferred aspect,the ketone is acetone. See, for example, Qureshi and Blaschek, 2003,supra.

In another preferred aspect, the fermentation product is an amino acid.In another more preferred aspect, the organic acid is aspartic acid. Inanother more preferred aspect, the amino acid is glutamic acid. Inanother more preferred aspect, the amino acid is glycine. In anothermore preferred aspect, the amino acid is lysine. In another morepreferred aspect, the amino acid is serine. In another more preferredaspect, the amino acid is threonine. See, for example, Richard, A., andMargaritis, A., 2004, Empirical modeling of batch fermentation kineticsfor poly(glutamic acid) production and other microbial biopolymers,Biotechnology and Bioengineering 87 (4): 501-515.

In another preferred aspect, the fermentation product is a gas. Inanother more preferred aspect, the gas is methane. In another morepreferred aspect, the gas is H₂. In another more preferred aspect, thegas is CO₂. In another more preferred aspect, the gas is CO. See, forexample, Kataoka, N., A. Miya, and K. Kiriyama, 1997, Studies onhydrogen production by continuous culture system of hydrogen-producinganaerobic bacteria, Water Science and Technology 36 (6-7): 41-47; andGunaseelan V. N. in Biomass and Bioenergy, Vol. 13 (1-2), pp. 83-114,1997, Anaerobic digestion of biomass for methane production: A review.

Recovery. The fermentation product(s) can be optionally recovered fromthe fermentation medium using any method known in the art including, butnot limited to, chromatography, electrophoretic procedures, differentialsolubility, distillation, or extraction. For example, alcohol isseparated from the fermented cellulosic material and purified byconventional methods of distillation. Ethanol with a purity of up toabout 96 vol. % can be obtained, which can be used as, for example, fuelethanol, drinking ethanol, i.e., potable neutral spirits, or industrialethanol.

Detergent Compositions

The polypeptides having cellulolytic enhancing activity of the presentinvention may be added to and thus become a component of a detergentcomposition.

The detergent composition of the present invention may be formulated,for example, as a hand or machine laundry detergent compositionincluding a laundry additive composition suitable for pre-treatment ofstained fabrics and a rinse added fabric softener composition, or beformulated as a detergent composition for use in general household hardsurface cleaning operations, or be formulated for hand or machinedishwashing operations.

In a specific aspect, the present invention provides a detergentadditive comprising a polypeptide of the invention. The detergentadditive as well as the detergent composition may comprise one or moreenzymes such as a protease, lipase, cutinase, an amylase, carbohydrase,cellulase, pectinase, mannanase, arabinase, galactanase, xylanase,oxidase, e.g., a laccase, and/or peroxidase.

In general the properties of the selected enzyme(s) should be compatiblewith the selected detergent, (i.e., pH-optimum, compatibility with otherenzymatic and non-enzymatic ingredients, etc.), and the enzyme(s) shouldbe present in effective amounts.

Cellulases: Suitable cellulases include those of bacterial or fungalorigin. Chemically modified or protein engineered mutants are included.Suitable cellulases include cellulases from the genera Bacillus,Pseudomonas, Humicola, Fusarium, Thielavia, Acremonium, e.g., the fungalcellulases produced from Humicola insolens, Myceliophthora thermophilaand Fusarium oxysporum disclosed in U.S. Pat. No. 4,435,307, U.S. Pat.No. 5,648,263, U.S. Pat. No. 5,691,178, U.S. Pat. No. 5,776,757 and WO89/09259.

Especially suitable cellulases are the alkaline or neutral cellulaseshaving color care benefits. Examples of such cellulases are cellulasesdescribed in EP 0 495 257, EP 0 531 372, WO 96/11262, WO 96/29397, WO98/08940. Other examples are cellulase variants such as those describedin WO 94/07998, EP 0 531 315, U.S. Pat. No. 5,457,046, U.S. Pat. No.5,686,593, U.S. Pat. No. 5,763,254, WO 95/24471, WO 98/12307 andPCT/DK98/00299.

Commercially available cellulases include CELLUZYME™, and CAREZYME™(Novozymes A/S), CLAZINASE™, and PURADAX HA™ (Genencor InternationalInc.), and KAC-500(B)™ (Kao Corporation).

Proteases: Suitable proteases include those of animal, vegetable ormicrobial origin. Microbial origin is preferred. Chemically modified orprotein engineered mutants are included. The protease may be a serineprotease or a metalloprotease, preferably an alkaline microbial proteaseor a trypsin-like protease. Examples of alkaline proteases aresubtilisins, especially those derived from Bacillus, e.g., subtilisinNovo, subtilisin Carlsberg, subtilisin 309, subtilisin 147 andsubtilisin 168 (described in WO 89/06279). Examples of trypsin-likeproteases are trypsin (e.g., of porcine or bovine origin) and theFusarium protease described in WO 89/06270 and WO 94/25583.

Examples of useful proteases are the variants described in WO 92/19729,WO 98/20115, WO 98/20116, and WO 98/34946, especially the variants withsubstitutions in one or more of the following positions: 27, 36, 57, 76,87, 97, 101, 104, 120, 123, 167, 170, 194, 206, 218, 222, 224, 235, and274.

Preferred commercially available protease enzymes include ALCALASE™SAVINASE™, PRIMASE™, DURALASE™, ESPERASE™, and KANNASE™ (Novozymes A/S),MAXATASE™, MAXACAL™, MAXAPEM™, PROPERASE™, PURAFECT™, PURAFECT OXP™,FN2™, and FN3™ (Genencor International Inc.).

Lipases: Suitable lipases include those of bacterial or fungal origin.Chemically modified or protein engineered mutants are included. Examplesof useful lipases include lipases from Humicola (synonym Thermomyces),e.g., from H. lanuginosa (T. lanuginosus) as described in EP 258 068 andEP 305 216 or from H. insolens as described in WO 96/13580, aPseudomonas lipase, e.g., from P. alcaligenes or P. pseudoalcaligenes(EP 218 272), P. cepacia (EP 331 376), P. stutzeri (GB 1,372,034), P.fluorescens, Pseudomonas sp. strain SD 705 (WO 95/06720 and WO96/27002), P. wisconsinensis (WO 96/12012), a Bacillus lipase, e.g.,from B. subtilis (Dartois et al., 1993, Biochemica et Biophysica Acta,1131: 253-360), B. stearothermophilus (JP 64/744992) or B. pumilus (WO91/16422).

Other examples are lipase variants such as those described in WO92/05249, WO 94/01541, EP 407 225, EP 260 105, WO 95/35381, WO 96/00292,WO 95/30744, WO 94/25578, WO 95/14783, WO 95/22615, WO 97/04079 and WO97/07202.

Preferred commercially available lipase enzymes include LIPOLASE™ andLIPOLASE ULTRA™ (Novozymes A/S).

Amylases: Suitable amylases (α and/or β) include those of bacterial orfungal origin. Chemically modified or protein engineered mutants areincluded. Amylases include, for example, α-amylases obtained fromBacillus, e.g., a special strain of Bacillus licheniformis, described inmore detail in GB 1,296,839.

Examples of useful amylases are the variants described in WO 94/02597,WO 94/18314, WO 96/23873, and WO 97/43424, especially the variants withsubstitutions in one or more of the following positions: 15, 23, 105,106, 124, 128, 133, 154, 156, 181, 188, 190, 197, 202, 208, 209, 243,264, 304, 305, 391, 408, and 444.

Commercially available amylases are DURAMYL™, TERMAMYL™, FUNGAMYL™ andBAN™ (Novozymes A/S), RAPIDASE™ and PURASTAR™ (from GenencorInternational Inc.).

Peroxidases/Oxidases: Suitable peroxidases/oxidases include those ofplant, bacterial or fungal origin. Chemically modified or proteinengineered mutants are included. Examples of useful peroxidases includeperoxidases from Coprinus, e.g., from C. cinereus, and variants thereofas those described in WO 93/24618, WO 95/10602, and WO 98/15257.

Commercially available peroxidases include GUARDZYME™ (Novozymes A/S).

The detergent enzyme(s) may be included in a detergent composition byadding separate additives containing one or more enzymes, or by adding acombined additive comprising all of these enzymes. A detergent additiveof the invention, i.e., a separate additive or a combined additive, canbe formulated, for example, as a granulate, liquid, slurry, etc.Preferred detergent additive formulations are granulates, in particularnon-dusting granulates, liquids, in particular stabilized liquids, orslurries.

Non-dusting granulates may be produced, e.g., as disclosed in U.S. Pat.Nos. 4,106,991 and 4,661,452 and may optionally be coated by methodsknown in the art. Examples of waxy coating materials are poly(ethyleneoxide) products (polyethyleneglycol, PEG) with mean molar weights of1000 to 20000; ethoxylated nonylphenols having from 16 to 50 ethyleneoxide units; ethoxylated fatty alcohols in which the alcohol containsfrom 12 to 20 carbon atoms and in which there are 15 to 80 ethyleneoxide units; fatty alcohols; fatty acids; and mono- and di- andtriglycerides of fatty acids. Examples of film-forming coating materialssuitable for application by fluid bed techniques are given in GB1483591. Liquid enzyme preparations may, for instance, be stabilized byadding a polyol such as propylene glycol, a sugar or sugar alcohol,lactic acid or boric acid according to established methods. Protectedenzymes may be prepared according to the method disclosed in EP 238,216.

The detergent composition of the invention may be in any convenientform, e.g., a bar, a tablet, a powder, a granule, a paste or a liquid. Aliquid detergent may be aqueous, typically containing up to 70% waterand 0-30% organic solvent, or non-aqueous.

The detergent composition comprises one or more surfactants, which maybe non-ionic including semi-polar and/or anionic and/or cationic and/orzwitterionic. The surfactants are typically present at a level of from0.1% to 60% by weight.

When included therein the detergent will usually contain from about 1%to about 40% of an anionic surfactant such as linearalkylbenzenesulfonate, alpha-olefinsulfonate, alkyl sulfate (fattyalcohol sulfate), alcohol ethoxysulfate, secondary alkanesulfonate,alpha-sulfo fatty acid methyl ester, alkyl- or alkenylsuccinic acid, orsoap.

When included therein the detergent will usually contain from about 0.2%to about 40% of a non-ionic surfactant such as alcohol ethoxylate,nonylphenol ethoxylate, alkylpolyglycoside, alkyldimethylamineoxide,ethoxylated fatty acid monoethanolamide, fatty acid monoethanolamide,polyhydroxy alkyl fatty acid amide, or N-acyl N-alkyl derivatives ofglucosamine (“glucamides”).

The detergent may contain 0-65% of a detergent builder or complexingagent such as zeolite, diphosphate, triphosphate, phosphonate,carbonate, citrate, nitrilotriacetic acid, ethylenediaminetetraaceticacid, diethylenetriaminepentaacetic acid, alkyl- or alkenylsuccinicacid, soluble silicates, or layered silicates (e.g., SKS-6 fromHoechst).

The detergent may comprise one or more polymers. Examples arecarboxymethylcellulose, poly(vinylpyrrolidone), poly (ethylene glycol),poly(vinyl alcohol), poly(vinylpyridine-N-oxide), poly(vinylimidazole),polycarboxylates such as polyacrylates, maleic/acrylic acid copolymers,and lauryl methacrylate/acrylic acid copolymers.

The detergent may contain a bleaching system which may comprise a H₂O₂source such as perborate or percarbonate which may be combined with aperacid-forming bleach activator such as tetraacetylethylenediamine ornonanoyloxybenzenesulfonate. Alternatively, the bleaching system maycomprise peroxyacids of, for example, the amide, imide, or sulfone type.

The enzyme(s) of the detergent composition of the invention may bestabilized using conventional stabilizing agents, e.g., a polyol such aspropylene glycol or glycerol, a sugar or sugar alcohol, lactic acid,boric acid, or a boric acid derivative, e.g., an aromatic borate ester,or a phenyl boronic acid derivative such as 4-formylphenyl boronic acid,and the composition may be formulated as described in, for example, WO92/19709 and WO 92/19708.

The detergent may also contain other conventional detergent ingredientssuch as, e.g., fabric conditioners including clays, foam boosters, sudssuppressors, anti-corrosion agents, soil-suspending agents, anti-soilredeposition agents, dyes, bactericides, optical brighteners,hydrotropes, tarnish inhibitors, or perfumes.

In the detergent compositions, any enzyme may be added in an amountcorresponding to 0.01-100 mg of enzyme protein per liter of wash liquor,preferably 0.05-5 mg of enzyme protein per liter of wash liquor, inparticular 0.1-1 mg of enzyme protein per liter of wash liquor.

In the detergent compositions, a polypeptide of the present inventionhaving cellulolytic enhancing activity may be added in an amountcorresponding to 0.001-100 mg of protein, preferably 0.005-50 mg ofprotein, more preferably 0.01-25 mg of protein, even more preferably0.05-10 mg of protein, most preferably 0.05-5 mg of protein, and evenmost preferably 0.01-1 mg of protein per liter of wash liquor.

A polypeptide of the invention having cellulolytic enhancing activitymay also be incorporated in the detergent formulations disclosed in WO97/07202, which is hereby incorporated by reference.

Signal Peptide

The present invention also relates to an isolated polynucleotideencoding a signal peptide comprising or consisting of amino acids 1 to21 of SEQ ID NO: 2. The present invention also relates to nucleic acidconstructs comprising a gene encoding a protein, wherein the gene isoperably linked to such a polynucleotide encoding a signal peptidecomprising or consisting of amino acids 1 to 21 of SEQ ID NO: 2, whereinthe gene is foreign to the polynucleotide encoding the signal peptide.

In a preferred aspect, the polynucleotide sequence comprises or consistsof nucleotides 1 to 63 of SEQ ID NO: 1.

The present invention also relates to recombinant expression vectors andrecombinant host cells comprising such nucleic acid constructs.

The present invention also relates to methods of producing a protein,comprising: (a) cultivating a recombinant host cell comprising a geneencoding a protein operably linked to such a polynucleotide encoding asignal peptide, wherein the gene is foreign to the polynucleotideencoding the signal peptide, under conditions conducive for productionof the protein; and (b) recovering the protein

The protein may be native or heterologous to a host cell. The term“protein” is not meant herein to refer to a specific length of theencoded product and, therefore, encompasses peptides, oligopeptides, andproteins. The term “protein” also encompasses two or more polypeptidescombined to form the encoded product. The proteins also include hybridpolypeptides that comprise a combination of partial or completepolypeptide sequences obtained from at least two different proteinswherein one or more (several) may be heterologous or native to the hostcell. Proteins further include naturally occurring allelic andengineered variations of the above mentioned proteins and hybridproteins.

Preferably, the protein is a hormone or variant thereof, enzyme,receptor or portion thereof, antibody or portion thereof, or reporter.In a more preferred aspect, the protein is an oxidoreductase,transferase, hydrolase, lyase, isomerase, or ligase. In an even morepreferred aspect, the protein is an aminopeptidase, amylase,carbohydrase, carboxypeptidase, catalase, cellulase, chitinase,cutinase, cyclodextrin glycosyltransferase, deoxyribonuclease, esterase,alpha-galactosidase, beta-galactosidase, glucoamylase,alpha-glucosidase, beta-glucosidase, invertase, laccase, another lipase,mannosidase, mutanase, oxidase, pectinolytic enzyme, peroxidase,phytase, polyphenoloxidase, proteolytic enzyme, ribonuclease,transglutaminase or xylanase.

The gene may be obtained from any prokaryotic, eukaryotic, or othersource.

The present invention is further described by the following examplesthat should not be construed as limiting the scope of the invention.

EXAMPLES

Chemicals used as buffers and substrates were commercial products of atleast reagent grade.

Strains

Thermoascus aurantiacus CGMCC 0670 was used as a source of a polypeptidehaving cellulolytic enhancing activity. Aspergillus oryzae JaL355 strain(WO 2005/070962) was used for expression of the Thermoascus aurantiacusCGMCC 0670 polypeptide having cellulolytic enhancing activity.

Media

PDA plates were composed of 39 grams of potato dextrose agar anddeionized water to 1 liter.

YG medium was composed of 5.0 g of yeast extract, 10.0 g of glucose, anddeionized water to 1 liter.

YG agar plates were composed of 5.0 g of yeast extract, 10.0 g ofglucose, 20.0 g of agar, and deionized water to 1 liter.

YPM medium was composed of 10 g of yeast extract, 20 of g Bacto peptone,20 g of maltose, and deionized water to 1 liter.

Wheat bran solid medium was composed of 30 g of wheat bran, 0.18 g ofyeast extract, 0.045 g of KH₂PO₄, 0.225 g of MgSO₄.7H₂O, 0.675 g ofglucose, and deionized water to 1 liter.

LB plates were composed of 10 g of tryptone, 5 g of yeast extract, 10 gof sodium chloride, 15 g of agar, and deionized water to 1 liter.

SOC medium was composed of 2% tryptone, 0.5% yeast extract, 10 mM NaCl,2.5 mM KCl, 10 mM MgCl₂, and 10 mM MgSO₄; sterilized by autoclaving andthen filter-sterilized glucose was added to 20 mM.

Example 1 Preparation of Thermoascus aurantiacus Strain CGMCC 0670Mycelia for cDNA Library Production

Thermoascus aurantiacus strain CGMCC 0670 was inoculated onto a YG agarplate and incubated for 4 days at 45° C. in the darkness. Severalmycelia-YG agar plugs were inoculated into 500 ml shake flaskscontaining 100 ml of YG medium. The flasks were incubated for 2 days at45° C. with shaking at 260 rpm. Then approximately 2 ml of the culturebroth were transferred to a 500 ml shake flask containing Wheat bransolid medium and the inoculated shake flask was incubated for 3 days at45° C. without shaking. The mycelia from the solid media were collectedand frozen in liquid nitrogen and then stored in a −80° C. freezer untiluse.

Example 2 Thermoascus aurantiacus Strain CGMCC 0670 RNA Isolation

The frozen mycelia were transferred into a liquid nitrogen prechilledmortar and pestle and ground to a fine powder with a small amount ofbaked quartz sand. Total RNA was prepared from the powdered mycelia byextraction with guanidinium thiocyanate followed by ultracentrifugationthrough a 5.7 M CsCl cushion according to Chirgwin et al., 1979,Biochemistry 18: 5294-5299. The polyA enriched RNA was isolated by oligo(dT)-cellulose affinity chromatography according to Aviv et al., 1972,Proc. Natl. Acad. Sci. USA 69: 1408-1412.

Example 3 Construction of a Thermoascus aurantiacus Strain CGMCC 0670cDNA Library

Double stranded cDNA was synthesized according to the general methods ofGubler and Hoffman, 1983, Gene 25: 263-269; Sambrook, J., Fritsch, E.F., and Maniatis, T. Molecular Cloning: A Laboratory Manual, 2^(nd) ed.,1989, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y.; and Kofodet al., 1994, J. Biol. Chem. 269: 29182-29189, using a Not I-(dT)₁₈primer (GE Healthcare Life Sciences, Piscataway, N.J., USA). Aftersynthesis, the cDNA was treated with mung bean nuclease, blunt endedwith T4 DNA polymerase, and ligated to an Eco RI adaptor (GE HealthcareLife Sciences, Piscataway, N.J., USA). The cDNA was cleaved with Not Iand the cDNA was size fractionated by 0.8% agarose gel electrophoresisusing 44 mM Tris base, 44 mM boric acid, 0.5 mM EDTA (TBE) buffer. Thefraction of cDNA of 700 by and larger was excised from the gel andpurified using a GFX® PCR DNA and Gel Band Purification Kit (GEHealthcare Life Sciences, Piscataway, N.J., USA) according to themanufacturer's instructions.

The prepared cDNA was then directionally cloned by ligation into EcoRI-Not I cleaved pMHas5 (WO 2004/013350) using T4 ligase (Promega,Madison, Wis., USA) according to the manufacturer's instructions. Theligation mixture was electroporated into E. coli DH10B cells (BoehringerMannheim, Indianapolis, Ind., USA) using a GENE PULSER® and PulseController (Bio-Rad Laboratories, Inc., Hercules, Calif., USA) at 200ohms, 25 mF, 1.8 kV with a 2 mm gap cuvette according to themanufacturer's procedure.

The electroporated cells were plated onto LB plates supplemented with100 μg of ampicillin per ml. A cDNA plasmid pool was prepared from30,000 total transformants of the original pMHas5 vector ligation.Plasmid DNA was prepared directly from the pool of colonies using aQIAGEN®-tip 100 (QIAGEN GmbH Corporation, Hilden, Germany).

Example 4 Construction of a SigA4 Transposon Containing theBeta-Lactamase Reporter Gene

A transposon containing plasmid designated pSigA4 was constructed fromthe pSigA2 transposon containing plasmid described in WO 2001/77315 inorder to create an improved version of the signal trapping transposon ofpSigA2 with decreased selection background. The pSigA2 transposoncontains a signal-less beta-lactamase construct encoded on thetransposon itself. PCR was used to create a deletion of the intactbeta-lactamase gene found on the plasmid backbone using a proofreadingPROOFSTART® DNA polymerase (QIAGEN GmbH Corporation, Hilden, Germany)and the following 5′ phosphorylated primers (TAG Copenhagen, Denmark):

SigA2NotU-P:

5′-TCGCGATCCGTTTTCGCATTTATCGTGAAACGCT-3′ (SEQ ID NO: 3)

SigA2NotD-P:

5′-CCGCAAACGCTGGTGAAAGTAAAAGATGCTGAA-3′ (SEQ ID NO: 4)

The amplification reaction was composed of 1 μl of pSigA2 (10 ng/μl), 5μl of 10×PROOFSTART® Buffer (QIAGEN GmbH Corporation, Hilden, Germany),2.5 μl of dNTP mix (20 mM), 0.5 μl of SigA2NotU-P (10 mM), 0.5 μl ofSigA2NotD-P (10 mM), 10 μl of Q solution (QIAGEN GmbH Corporation,Hilden, Germany), and 31.25 μl of deionized water. The amplificationreaction was incubated in a PTC-200 DNA ENGINE™ Thermal Cycler (MJResearch Inc., Waltham, Mass., USA) programmed for 1 cycle at 95° C. for5 minutes; and 20 cycles each at 94° C. for 30 seconds, 62° C. for 30seconds, and 72° C. for 4 minutes.

A 3.9 kb PCR reaction product was isolated by 0.8% agarose gelelectrophoresis using 40 mM Tris base-20 mM sodium acetate-1 mM disodiumEDTA (TAE) buffer and 0.1 μg of ethidium bromide per ml. The DNA bandwas visualized with the aid of an EAGLE EYE® Imaging System (Stratagene,La Jolla, Calif., USA) at 360 nm. The 3.9 kb DNA band was excised fromthe gel and purified using a GFX® PCR DNA and Gel Band Purification Kitaccording to the manufacturer's instructions.

The 3.9 kb fragment was self-ligated at 16° C. overnight with 10 unitsof T4 DNA ligase (New England Biolabs, Inc., Beverly, Mass., USA), 9 μlof the 3.9 kb PCR fragment, and 1 μl of 10× ligation buffer (New EnglandBiolabs, Inc., Beverly, Mass., USA). The ligation reaction was heatinactivated for 10 minutes at 65° C. and then digested with Dpn I at 37°C. for 2 hours. After incubation, the digestion was purified using aGFX® PCR DNA and Gel Band Purification Kit.

The purified material was then transformed into E. coli TOP10 competentcells (Invitrogen Corp., Carlsbad, Calif., USA) according to themanufacturer's instructions. The transformation mixture was plated ontoLB plates supplemented with 25 μg of chloramphenicol per ml. Plasmidminipreps were prepared from several transformants and digested with BglII. One plasmid with the correct construction was chosen. The plasmidwas designated pSigA4. Plasmid pSigA4 contains the Bgl II flankedtransposon SigA2 identical to that disclosed in WO 01/77315.

A 60 μl sample of plasmid pSigA4 DNA (0.3 μg/μl) was digested with BglII and separated by 0.8% agarose gel electrophoresis using TBE buffer. ASigA2 transposon DNA band of 2 kb was eluted with 200 μl of EB buffer(QIAGEN GmbH Corporation, Hilden, Germany) and purified using a GFX® PCRDNA and Gel Band Purification Kit according to the manufacturer'sinstructions and eluted in 200 μl of EB buffer. SigA2 was used fortransposon assisted signal trapping.

Example 5 Transposon Assisted Signal Trapping of Thermoascus aurantiacusCGMCC 0670

A complete description of transposon assisted signal trapping can befound in WO 2001/77315. A cDNA plasmid pool was prepared from 50,000total transformants of the original cDNA-pMHas5 vector ligation. PlasmidDNA was prepared directly from a pool of colonies recovered from LBplates supplemented with 100 μg of ampicillin per ml using a QIAPREP®Spin Midi/Maxiprep Kit (QIAGEN GmbH Corporation, Hilden, Germany). Theplasmid pool was treated with transposon SigA2 and MuA transposase(Finnzymes OY, Espoo, Finland) according to the manufacturer'sinstructions.

For in vitro transposon tagging of the Thermoascus aurantiacus CGMCC NO.0670 cDNA library, 4 μl of SigA2 transposon containing approximately 100ng of DNA were mixed with 5 μl of the plasmid DNA pool of theThermoascus aurantiacus CGMCC NO. 0670 cDNA library containing 3 μg ofDNA, 1 μl of MuA transposase (0.22 μg/μl), and 4 μl of 5× buffer(Finnzymes OY, Espoo, Finland) in a total volume of 20 μl and incubatedat 37° C. for 2.5 hours followed by heat inactivation at 70° C. for 10minutes. The DNA was precipitated by addition of 2 μl of 3 M sodiumacetate pH 5 and 55 μl of 96% ethanol and centrifuged for 30 minutes at10,000×g, 4° C. The pellet was washed in 70% ethanol, air dried at roomtemperature, and resuspended in 7 μl of deionized water.

A 1.5 μl volume of the transposon tagged plasmid pool was electroporatedinto 40 μl of E. coli ElectroMAX DH10B cells (Invitrogen Corp.,Carlsbad, Calif., USA) according to the manufacturer's instructionsusing a GENE PULSER® and Pulse Controller at 25 uF, 25 mAmp, 2.5 kV witha 2 mm gap cuvette according to the manufacturer's procedure.

The electroporated cells were incubated in SOC medium with shaking at225 rpm for 1 hour at 37° C. before being plated on the followingselective media: LB medium supplemented with 50 μg of kanamycin per ml;LB medium supplemented with 50 μg of kanamycin per ml and 15 μg ofchloramphenicol per ml; and LB medium supplemented with 50 μg ofkanamycin per ml, 15 μg of chloramphencol per ml, and 15 μg ofampicillin per ml.

From plating of the electroporation onto LB medium supplemented with 50μg of kanamycin per ml, 15 μg of chloramphencol per ml, and 15 μg ofampicillin per ml, approximately 269 colonies were observed after 3 daysat 30° C. All colonies were replica plated onto LB plates supplementedwith 50 μg of kanamycin, 15 μg of chloramphenicol with 50 μg ofampicillin per ml. A total of 188 colonies were recovered under thisselection condition. Further electroporation and plating experimentswere performed until 550 total colonies were recovered under tripleselection. The colonies were miniprepped using a QIAPREP® 96 TurboMiniprep Kit (QIAGEN GmbH Corporation, Hilden, Germany). Plasmids weresequenced with the transposon forward and reverse primers (primers A andB), shown below, according to the procedure disclosed in WO 01/77315(page 28).

Primer A:

5′-AGCGTTTGCGGCCGCGATCC-3′ (SEQ ID NO: 5)

Primer B:

5′-TTATTCGGTCGAAAAGGATC C-3′ (SEQ ID NO: 6)

Example 6 Sequence Assembly and Annotation

DNA sequences were obtained for the reactions on a MEGABACE™ 500 DNAAnalysis System (GE Healthcare Life Sciences, Piscataway, N.J., USA).Primer A and primer B sequence reads for each plasmid were trimmed toremove vector and transposon sequence, which resulted in 208 assembledsequences that were grouped into 83 contigs by using the programPhredPhrap (Ewing et al., 1998, Genome Research 8: 175-185; Ewing andGreen, 1998, Genome Research 8: 186-194). All 83 contigs weresubsequently compared to sequences available in standard public DNA andprotein sequences databases (TrEMBL, SWALL, PDB, EnsemblPep, GeneSeqP)using the program BLASTX 2.0a19MP-WashU [14 Jul. 1998] [Build linux-x8618:51:44 30 Jul. 1998] (Gish et al., 1993, Nat. Genet. 3: 266-72). Thefamily GH61B candidate was identified directly by analysis of the BlastXresults.

Example 7 Cloning of the Thermoascus aurantiacus gh61b Gene from GenomicDNA

Based on the cDNA sequence, oligonucleotide primers, shown below, weredesigned to amplify the gh61b gene from genomic DNA of Thermoascusaurantiacus strain CGMCC 0670.

Sense primer:

5′-TATCAATTGATGTCGTTCTCGAAGATTGCTG-3′ (SEQ ID NO: 7)

Antisense primer:

5′-TATGCGGCCGCTCTGTTCAGCGCATGTCGTT-3′ (SEQ ID NO: 8)

The amplification reaction was composed of 1×REDDYMIX™ PCR Buffer(Thermo Fisher Scientific Inc., Waltham, Mass., USA), 0.75 units ofThermoPrime Taq DNA Polymerase (Thermo Fisher Scientific Inc., Waltham,Mass., USA), 75 mM Tris-HCl (pH 8.8 at 25° C.), 20 mM (NH₄)₂SO₄, 0.01%(v/v) TWEEN® 20, 0.2 mM dNTPs, and 1.5 mM MgCl₂, as well as 0.2 μM ofeach primer and 0.5-1 μg of T. aurantiacus genomic DNA (isolated usingstandard methods). The amplification reaction was incubated in a PTC-200DNA ENGINE™ Thermal Cycler programmed for 2 minutes initial denaturationat 94° C., followed by 35 cycles each at 94° C. for 15 seconds andcombined annealing and extension at 60° C. for 2 minutes.

A PCR product of approximately 1.1 kb was purified by 1% agarose gelelectrophoresis using TAE buffer, excised from the gel, and purifiedusing a GFX® PCR DNA and Gel Band Purification Kit according to themanufacturer's instructions. The purified DNA band was then cloned intoplasmid pXYG1051 (WO 2005/080559) digested with Mfe I/Not I. Four of theresulting plasmid inserts were subjected to Sanger sequencing usingstandard techniques. All of the plasmids contained mutations apparentlyintroduced by the PCR amplification. One plasmid having only silentmutations in the coding region was selected for further work anddesignated pXYG1051-ND001860 long (FIG. 2). The expression vectorpXYG1051 contains the same neutral amylase II (NA2) promoter derivedfrom Aspergillus niger, and terminator elements as pCaHj483 (disclosedin Example 4 of WO 98/00529). Furthermore pXYG1051 has pUC18 derivedsequences for selection and propagation in E. coli, and pDSY82(disclosed in Example 4 of U.S. Pat. No. 5,958,727) derived sequencesfor selection and expression in Aspergillus facilitated by the pyrG geneof Aspergillus oryzae, which encodes orotidine decarboxylase and is usedto complement a pyrG mutant Aspergillus strain.

In order to subclone the Thermoascus aurantiacus GH61B polypeptide geneinto pCR®2.1 (Invitrogen, Carlsbad, Calif., USA), the long fragmentcontaining the CDS and an intron was amplified by PCR frompXYG1051-ND001860 long using primers ND1860-3F and ND1860-2R, shownbelow, containing Hind III and Not I restriction sites, respectively, toallow for subcloning into pCR®2.1.

ND1860-3F:

5′-cccaagcttatgtcgttctcgaagattgctg-3′ (SEQ ID NO: 9)

ND1860-2R:

5′-tatgcggccgctctgttcagcgcatgtcgtt-3′ (SEQ ID NO: 10)

The amplification reaction was composed of 1×REDDYMIX™ PCR Buffer, 0.75units of ThermoPrime Taq DNA polymerase, 75 mM Tris-HCl (pH 8.8 at 25°C.), 20 mM (NH₄)₂SO₄, 0.01% (v/v) TWEEN® 20, 0.2 mM dNTPs, and 1.5 mMMgCl₂, as well as 0.2 μM of each primer and 0.1 μg of the plasmid DNA.The amplification reaction was incubated in a PTC-200 DNA ENGINE™Thermal Cycler programmed for 2 minutes initial denaturation at 94° C.,followed by 25 cycles each at 94° C. for 15 seconds and combinedannealing and extension at 60° C. for 2 minutes.

The amplified product was gel purified using a GFX® PCR DNA and Gel BandPurification Kit according to the manufacturer's instructions. The HindIII and Not I digested PCR product was then cloned by ligation intopCR®2.1 digested with Hind III-Not I using standard molecular biologytechniques to yield pXYZ1473 (FIG. 3). The Thermoascus aurantiacus GH61Bpolypeptide gene insert in pXYZ1473 was confirmed by Sanger sequencing.E. coli pXYZ1473 was deposited with the Deutsche Sammlung vonMikroorganismen and Zellkulturen GmbH (DSM) on Dec. 2, 2008 and assignedaccession number DSM 22075.

Example 8 Characterization of the Thermoascus aurantiacus GenomicSequence Encoding a Family GH61B Polypeptide Having CellulolyticEnhancing Activity

The nucleotide sequence (SEQ ID NO: 1) and deduced amino acid sequence(SEQ ID NO: 2) of the Thermoascus aurantiacus GH61B polypeptide havingcellulolytic enhancing activity genomic DNA sequence are shown inFIG. 1. The genomic polynucleotide is 1115 bp (including stop codon),interrupted by 1 intron of 50 bp, and encodes a polypeptide of 354 aminoacids. The % G+C content of the full-length coding sequence and themature coding sequence, including the intron, is 55.2% and 55.8%,respectively. Using the SignalP software program (Nielsen et al., 1997,Protein Engineering 10:1-6), a signal peptide of 21 residues waspredicted. The predicted mature protein contains 333 amino acids with amolecular mass of 34.6 kDa.

Analysis of the deduced amino acid sequence of the GH61B polypeptidehaving cellulolytic enhancing activity with the Interproscan program(Mulder et al., 2007, Nucleic Acids Res. 35: D224-D228) showed that theGH61B polypeptide contained the sequence signature of glycosidehydrolase Family 61 (InterPro accession IPR005103). This sequencesignature was found from approximately residues 1 to 220 of the maturepolypeptide (Pfam accession PF03443).

A comparative pairwise global alignment of amino acid sequences wasdetermined using the Needleman-Wunsch algorithm (Needleman and Wunsch,1970, J. Mol. Biol. 48: 443-453) as implemented in the Needle program ofEMBOSS with gap open penalty of 10, gap extension penalty of 0.5, andthe EBLOSUM62 matrix. The alignment showed that the deduced amino acidsequence of the Thermoascus aurantiacus GH61B mature polypeptide shared77.2% sequence identity (excluding gaps) to the deduced amino acidsequence of another Family 61 glycoside hydrolase protein fromThermoascus aurantiacus (GeneSeqP accession number AECO5922).

Example 9 Production of Recombinant Thermoascus aurantiacus GH61BPolypeptide Having Cellulolytic Enhancing Activity in Aspergillus oryzae

The expression plasmid pXYG1051-ND001860 long was transformed intoAspergillus oryzae JaL355 according to the protocol described in WO98/00529. Transformants were purified on selection plates through singleconidia prior to sporulating them on PDA plates. Production of theThermoascus aurantiacus GH61B polypeptide by the transformants wasanalyzed from culture supernatants of 1 ml 96 deep well stationarycultivations at 26° C. in YP medium with 2% maltodextrin. Expression wasverified by NU-PAGE® 10% Bis-Tris SDS-PAGE (Invitrogen, Carlsbad,Calif., USA) by Coomassie staining. One transformant was selected forfurther work and designated Aspergillus oryzae ND1860.

For larger scale production, Aspergillus oryzae ND1860 spores werespread onto a PDA plate and incubated for five days at 34° C. Theconfluent spore plate was washed twice with 5 ml of 0.01% TWEEN® 20 tomaximize the number of spores collected. The spore suspension was thenused to inoculate 100 ml of YPM medium in a 500 ml flask. The culturewas incubated at 28° C. with constant shaking at 200 rpm. At day fourpost-inoculation, the culture broth was collected by filtration througha 0.22 μm EXPRESS™ Plus Membrane (Millipore, Bedford, Mass., USA). Freshculture broth produced a band of GH61B protein of approximately 50 kDa.Upon subsequent incubation of culture broth at 4° C., the approximately50 kDa band slowly degraded to predominant bands of approximately 37 kDaand approximately 25 kDa. The identity of these bands as fragments ofthe Thermoascus aurantiacus GH61B polypeptide was verified by massspectrometry.

Example 10 Assay of Cellulolytic Enhancing Activity of Thermoascusaurantiacus GH61B Polypeptide

Culture broth of Aspergillus oryzae ND1860 was prepared as described inExample 9. The culture broth was concentrated approximately 20-foldusing an Amicon ultrafiltration device (Millipore, Bedford, Mass., USA;10 kDa polyethersulfone membrane, 40 psi, 4° C.). The concentratedculture broth was desalted (HIPREP™ 26/10 desalting column, GEHealthcare, Piscataway, N.J., USA) into 20 mM Tris-HCl pH 8.0 and thenapplied to a 20 ml MONO Q™ column (HR 16/10, GE Healthcare, Piscataway,N.J., USA) equilibrated with 20 mM Tris-HCl pH 8.0. Bound proteins wereeluted with a 15 column volume salt gradient from 0 mM to 500 mM NaCl in20 mM Tris-HCl pH 8.0. Fractions were examined by 8-16% SDS-PAGE gelsand revealed that the 25 kDa polypeptide eluted at approximately 160 mMNaCl while the approximately 50 kDa polypeptide eluted at approximately210 mM NaCl. Both samples were >85% pure as judged by SDS-PAGE gel.Protein concentration was estimated by densitometry following SDS-PAGEand Coomassie blue staining. Corn stover was pretreated and prepared asan assay substrate according to WO 2005/074647 to generate pretreatedcorn stover (PCS). The base cellulase mixture used to assay enhancingactivity was prepared from Trichoderma reesei strain SMA135 (WO2008/057637).

Hydrolysis of PCS was conducted using 1.6 ml deep-well plates (Axygen,Santa Clara, Calif., USA) using a total reaction volume of 1.0 ml and aPCS concentration of 50 mg/ml in 1 mM manganese sulfate-50 mM sodiumacetate pH 5.0. Each T. aurantiacus GH61B polypeptide was added to thebase cellulase mixture at concentrations ranging from 0 to 100% of theprotein concentration of the base cellulase mixture. Incubation was at50° C. for 168 hours. Assays were typically performed in triplicate.Aliquots were centrifuged, and the supernatant liquid was filtered bycentrifugation (MULTISCREEN® HV 0.45 μm, Millipore, Billerica, Mass.,USA) at 3000 rpm for 10 minutes using a plate centrifuge (SORVALL® RT7,Thermo Fisher Scientific, Waltham, Mass., USA). When not usedimmediately, filtered hydrolysate aliquots were frozen at −20° C. Sugarconcentrations of samples diluted in 0.005 M H₂SO₄ with 0.05% w/wbenzoic acid were measured after elution by 0.005 M H₂SO₄ with 0.05% w/wbenzoic acid at a flow rate of 0.6 ml/minute from a 4.6×250 mm AMINEX®HPX-87H column (Bio-Rad Laboratories, Inc., Hercules, Calif., USA) at65° C. with quantitation by integration of glucose and cellobiosesignals using refractive index detection (CHEMSTATION®, AGILENT® 1100HPLC, Agilent Technologies, Santa Clara, Calif., USA) calibrated by puresugar samples (Absolute Standards Inc., Hamden, Conn., USA). Theresultant equivalents were used to calculate the percentage of celluloseconversion for each reaction. The degree of cellulose conversion toglucose plus cellobiose sugars (conversion, %) was calculated using thefollowing equation:Conversion (%)=(glucose+cellobiose×1.053)(mg/ml)×100×162/(cellulose(mg/ml)×180)=(glucose+cellobiose×1.053)(mg/ml)×100/(cellulose(mg/ml)×1.111)In this equation the factor 1.111 reflects the weight gain in convertingcellulose to glucose, and the factor 1.053 reflects the weight gain inconverting cellobiose to glucose. Cellulose in PCS was determined by alimit digest of PCS to release glucose and cellobiose.

The results of adding increasing amounts of Thermoascus aurantiacusGH61B polypeptide to the base cellulase mix are shown in FIG. 4. Theperformance of the base cellulase mix is shown by the horizontal line inFIG. 4. Addition of the approximately 25 kDa T. aurantiacus GH61Bpolypeptide allowed for reduction of the total protein loading to reach80% glucan conversion by a factor of at least 1.50-fold. In contrast,addition of the approximately 50 kDa T. aurantiacus GH61B polypeptidedid not provide for a reduction of the total protein loading to reach80% glucan conversion suggesting that the approximately 25 kDapolypeptide is the active form of T. aurantiacus GH61B.

DEPOSIT OF BIOLOGICAL MATERIAL

The following biological material has been deposited under the terms ofthe Budapest Treaty with the Deutsche Sammlung von Mikroorganismen andZellkulturen GmbH (DSM), Mascheroder Weg 1 B, D-38124 Braunschweig,Germany, and given the following accession number:

Deposit Accession Number Date of Deposit E. coli pXYZ1473 DSM 22075 Dec.2, 2008

The strain has been deposited under conditions that assure that accessto the culture will be available during the pendency of this patentapplication to one determined by foreign patent laws to be entitledthereto. The deposit represents a substantially pure culture of thedeposited strain. The deposit is available as required by foreign patentlaws in countries wherein counterparts of the subject application, orits progeny are filed. However, it should be understood that theavailability of a deposit does not constitute a license to practice thesubject invention in derogation of patent rights granted by governmentalaction.

The invention described and claimed herein is not to be limited in scopeby the specific aspects herein disclosed, since these aspects areintended as illustrations of several aspects of the invention. Anyequivalent aspects are intended to be within the scope of thisinvention. Indeed, various modifications of the invention in addition tothose shown and described herein will become apparent to those skilledin the art from the foregoing description. Such modifications are alsointended to fall within the scope of the appended claims. In the case ofconflict, the present disclosure including definitions will control.

1. An isolated polypeptide having cellulolytic enhancing activity,selected from the group consisting of: (a) a polypeptide comprising anamino acid sequence having at least 95% sequence identity to the maturepolypeptide of SEQ ID NO: 2; (b) a polypeptide encoded by apolynucleotide that hybridizes under high stringency conditions with (i)the complement of the mature polypeptide coding sequence of SEQ ID NO:1, or (ii) the complement of the cDNA sequence contained in the maturepolypeptide coding sequence of SEQ ID NO: 1, wherein high stringencyconditions are defined as hybridization at 42° C. in 5×SSPE, 0.3% SDS,200 μg/ml sheared and denatured salmon sperm DNA, and 50% formamide andwashing three times each for 15 minutes using 2×SSC, 0.2% SDS at 65° C.;and (c) a polypeptide comprising or consisting of the amino acidsequence of SEQ ID NO: 2; or a fragment thereof having cellulolyticenhancing activity.
 2. The polypeptide of claim 1, which is encoded bythe polynucleotide contained in plasmid pXYZ1473 which is contained inE. coli DSM
 22075. 3. The polypeptide of claim 1, which comprises anamino acid sequence having at least 95% sequence identity to the maturepolypeptide of SEQ ID NO:
 2. 4. The polypeptide of claim 3, whichcomprises an amino acid sequence having at least 97% sequence identityto the mature polypeptide of SEQ ID NO:
 2. 5. The polypeptide of claim1, which is encoded by a polynucleotide that hybridizes under highstringency conditions with (i) the complement of the mature polypeptidecoding sequence of SEQ ID NO: 1, or (ii) the complement of the cDNAsequence contained in the mature polypeptide coding sequence of SEQ IDNO: 1, wherein high stringency conditions are defined as hybridizationat 42° C. in 5×SSPE, 0.3% SDS, 200 μg/ml sheared and denatured salmonsperm DNA, and 50% formamide and washing three times each for 15 minutesusing 2×SSC, 0.2% SDS at 65° C.
 6. The polypeptide of claim 5, which isencoded by a polynucleotide that hybridizes under very high stringencyconditions with (i) the complement of the mature polypeptide codingsequence of SEQ ID NO: 1, or (ii) the complement of the cDNA sequencecontained in the mature polypeptide coding sequence of SEQ ID NO: 1,wherein very high stringency conditions are defined as hybridization at42° C. in 5×SSPE, 0.3% SDS, 200 μg/ml sheared and denatured salmon spermDNA, and 50% formamide and washing three times each for 15 minutes using2×SSC, 0.2% SDS at 70° C.
 7. The polypeptide of claim 1, which comprisesor consists of the amino acid sequence of SEQ ID NO: 2; or a fragmentthereof having cellulolytic enhancing activity.
 8. The polypeptide ofclaim 7, which comprises or consists of the mature polypeptide of SEQ IDNO:
 2. 9. A detergent composition comprising one or more cellulolyticenzymes and the polypeptide of claim
 1. 10. A method for degrading orconverting a cellulosic material, comprising: treating the cellulosicmaterial with an enzyme composition comprising one or more cellulolyticenzymes in the presence of the polypeptide having cellulolytic enhancingactivity of claim
 1. 11. The method of claim 10, wherein the cellulosicmaterial is pretreated.
 12. The method of claim 10, wherein the one ormore cellulolytic enzymes are selected from the group consisting of anendoglucanase, a cellobiohydrolase, and a beta-glucosidase.
 13. Themethod of claim 10, wherein the enzyme composition further comprises oneor more enzymes selected from the group consisting of a xylanase, ahemicellulase, an esterase, a protease, a laccase, and a peroxidase. 14.The method of claim 10, further comprising recovering the degradedcellulosic material.
 15. The method of claim 14, wherein the degradedcellulosic material is a sugar.
 16. A method for producing afermentation product, comprising: (a) saccharifying a cellulosicmaterial with an enzyme composition comprising one or more cellulolyticenzymes in the presence of the polypeptide having cellulolytic enhancingactivity of claim 1; (b) fermenting the saccharified cellulosic materialwith one or more fermenting microorganisms to produce the fermentationproduct; and (c) recovering the fermentation product from thefermentation.
 17. The method of claim 16, wherein the cellulosicmaterial is pretreated.
 18. The method of claim 16, wherein the one ormore cellulolytic enzymes are selected from the group consisting of anendoglucanase, a cellobiohydrolase, and a beta-glucosidase.
 19. Themethod of claim 16, wherein the enzyme composition further comprises oneor more enzymes selected from the group consisting of a xylanase, ahemicellulase, an esterase, a protease, a laccase, and a peroxidase. 20.The method of claim 16, wherein steps (a) and (b) are performedsimultaneously in a simultaneous saccharification and fermentation. 21.The method of claim 16, wherein the fermentation product is an alcohol,an organic acid, a ketone, an amino acid, or a gas.
 22. A method offermenting a cellulosic material, comprising: fermenting the cellulosicmaterial with one or more fermenting microorganisms, wherein thecellulosic material is saccharified with an enzyme compositioncomprising one or more cellulolytic enzymes in the presence of apolypeptide having cellulolytic enhancing activity of claim
 1. 23. Themethod of claim 22, wherein the fermenting of the cellulosic materialproduces a fermentation product.
 24. The method of claim 23, furthercomprising recovering the fermentation product from the fermentation.25. The method of claim 22, wherein the cellulosic material ispretreated before saccharification.
 26. The method of claim 22, whereinthe one or more cellulolytic enzymes are selected from the groupconsisting of an endoglucanase, a cellobiohydrolase, and abeta-glucosidase.
 27. The method of claim 22, wherein the enzymecomposition further comprises one or more enzymes selected from thegroup consisting of a xylanase, a hemicellulase, an esterase, aprotease, a laccase, and a peroxidase.
 28. The method of claim 23,wherein the fermentation product is an alcohol, an organic acid, aketone, an amino acid, or a gas.